Cell phone technology and physical surveillance.

Rapid changes in technology often present law enforcement with questions as to how these advances fit within an already-existing legal framework of laws and cases. The widespread availability of the cell phone is no different. Law enforcement has been presented with an investigative instrument capable of augmenting tools used to assist physical surveillance such as traditional tracking equipment. (1) Yet, the parameters for the lawful use of this technology to assist law enforcement are not yet fully delineated. The traditional statutory framework governing electronic surveillance does not provide law enforcement with clear-cut guidance. This article covers the use of the cell phone as a surveillance aid and the extent to which current electronic surveillance statutory provisions address this use. In addition, the recent judicial analysis of this issue also will be discussed.

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Traditional Tracking Analysis

Traditional law enforcement methods of tracking, whether through the use of a tracking device on a vehicle or other conveyance or placing a device inside a container, fit within the analysis provided by the U.S. Supreme Court in United States v. Knotts (2) and United States v. Karo. (3) These cases held that so long as the conveyance or thing to be monitored is out and about on the public thoroughfares, (4) open fields, or even on private property, (5) all instances where the information revealed by the target could be observed by visual surveillance engaged in by third parties, no showing of evidence--let alone probable cause--is required. (6) This analysis holds true today so long as the tracking equipment belongs to the government; it does not resolve the issue when third-party assistance from the service provider is required.

Cell phone companies with mounting concerns about liability typically will not furnish cell phone location information to law enforcement absent a court order. The question of the moment surrounds the quantum of evidence that the government must articulate to a court before such an order for prospective or real-time data (critical for tracking the cell phone) will be issued. (7)

Within the Scope of an Existing Court Order

In United States v. Forest, (8) the DEA had a court order to intercept wire communications pursuant to "Title III" (9) that also directed the service provider to "disclose to the government all subscriber information, toll records, and other information relevant to the government's investigation." (10) As an aid to the establishment of visual contact with the subject, DEA personnel dialed the target's cell phone (without letting it ring) several times in the course of the day and obtained the cell phone location through the cell site information given by the service provider. (11)

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The defendant argued that in so doing, DEA personnel violated his Fourth Amendment rights. The threshold question was whether securing the cell site location information constituted either a search or a seizure within the meaning of the Fourth Amendment. The Federal Court of Appeals for the Sixth Circuit concluded that because the data "was used to track [the target's] movements only on public highways," Knotts was controlling and that there was "no legitimate expectation of privacy in the cell site data because DEA agents could have obtained the same information by following [the target's] car." (12)

Absent an Existing Court Order

In most location surveillance scenarios, law enforcement probably will not be fortunate enough to have a comprehensive court order in place as in Forest, thus squarely presenting the need for a standalone order. The type of order and quantum of information needed to obtain this information from the service provider are not yet clear. In several instances, federal law enforcement has relied on provisions within Title II of the Electronic Communications Privacy Act (13) (ECPA), primarily section 2703(d) of Title 18 of the U.S. Code (U.S.C.) either alone or in combination with the pen register and trap and trace statute, Title 18 at sections 3121-3127 (hereafter referred to as the pen/trap statute). (14)

This approach, however, has not proved to be entirely successful. In a series of late 2005 and early 2006 requests by the government in federal court seeking cell site information for tracking purposes, several federal courts have concluded that the equivalent of a search warrant based upon probable cause is required to compel a service provider to divulge real-time/prospective cell site location information. This contrasts with the government's attempt to use the pen/trap statute in conjunction with a 2703(d) court order. The latter is predicated on "specific and articulable facts showing that there are reasonable grounds to believe that the contents of a wire or electronic communication or the records or other information sought are relevant and material to an ongoing criminal investigation."

In two late 2005 cases out of the Eastern District of New York, the U.S. Attorney's Office (USAO) sought an order compelling the "disclosure of the location of cell site/sector (physical address) at call origination (for outbound calling), call termination (for incoming calls), and if reasonably available, during the progress of a call, for the Subject Telephone." (15) In support of its request, the government cited three provisions within section 2703, including subsection (d). Of the sections proffered, the U.S. magistrate judge found that only 2703(d) might provide a basis for the order sought. The U.S. magistrate judge concluded that the government had provided the requisite level of evidence called for in 2703(d) and that under the statutory definition, (16) cell site location information would constitute the "contents of ... [an] electronic communication" except for one thing, the definition of electronic communication (17) specifically excludes "any communication from a tracking device." A tracking device is defined as "an electronic or mechanical device which permits the tracking of the movement of a person or object." (18) The court concluded that based upon these statutory definitions, the targeted cell phone equated to--and was thus "precisely describe[d]" as--a tracking device. Thus, the court concluded that it was unable to grant the government's application for a tracking order.

Because the government's application also sought permission to conduct pen register, as well as trap and trace, operations, the court held that "[i]n fairness ... [it] must also consider whether the relief is available simply by virtue of the government's otherwise proper application" for this additional authority. (19) The U.S. magistrate judge concluded that the pen/trap statute did not provide such a basis because specific language in the Communications Assistance for Law Enforcement Act (CALEA) (20) precluded it. Among other things, CALEA mandated that telecommunications carriers be technologically able to

   expeditiously isolat[e] and enabl[e] the government, pursuant to a
   court order or other lawful authorization, to access
   call-identifying information ... except that with regard to
   information acquired solely pursuant to the authority for pen
   registers and trap and trace devices ..., such call-identifying
   information shall not include any information that may disclose the
   physical location of the subscriber. (21)

The U.S. magistrate judge further stated that "where a carrier's assistance to law enforcement is ordered on the basis of something less than probable cause, such assistance must not include disclosure of a subscriber's physical location." (22) Upon reconsideration, the court again denied the gov-ernment's request for real-time cell site information reiterating, "existing law does not permit the government to obtain the requested information on a prospective, real-time basis without a showing of probable cause." (23)

In a request in the Southern District of Texas, (24) the government combined a pen register and trap/trace request with one seeking subscriber records. The application also sought, in part, the prospective/real-time "location of cell site/sector (physical address) at call origination (for outbound calling), call termination (for incoming calls) and, if reasonably available, during the progress of a call." (25) In addition to this, the government also requested data to include "information regarding the strength, angle, and timing of the caller's signal measured at two or more cell sites ...." (26) The question the U.S. magistrate judge found himself confronting was whether

   this location information [is] merely another form of subscriber
   record accessible upon a showing of "specific and articulable facts"
   under 18 U.S.C. [section] 2703(d), as the government contends, [or
   whether] this type of surveillance require[s] a more exacting
   standard such as probable cause under Federal Rule of Criminal
   Procedure 41[.] (27)

Like the New York U.S. magistrate judge, the court rejected all of the government's theories--the pen/trap statute, the Stored Communications Act, and the hybrid mix of the two. The court then stated, "[d]enial of the government's request for prospective cell site data in this instance should have no dire consequences for law enforcement. This type of surveillance is unquestionably available upon a traditional probable cause showing under Rule 41." (28)

The government again sought an order relying on its hybrid theory advanced in the request described above and again was denied next by a U.S. magistrate judge in Maryland. (29) Although the outcome for the government was the same here as in the earlier court decisions, the U.S. magistrate judge in this request at least recognized--but to no effect on the ultimate outcome--that "[i]f acquisition of real-time cell site information is equivalent to a tracking device, it would seem the government is not constitutionally required to obtain a warrant provided the phone remains in a public place where visual surveillance would be available." (30)

Given the less than fully successful results achieved so far, in a request for an order before a U.S. magistrate judge in the District of Columbia, the government tried a different approach by attempting a union of the Fourth Amendment with a 2703(d) court order. In this request, the government sought a court order by "demonstrat[ing] probable cause to believe that the requested prospective cell site information is relevant and material to an ongoing criminal investigation." (31)

The court rejected the government's approach, acknowledging the probable cause showing but concluding that this did not help the government overcome the fact that "the statutes upon which the government purports to rely on in those cases and in this one ... do not authorize the government to secure cell site data that would disclose the location of the person using the cell phone," and, in the court's analogy, that the attempt was akin to designing a horse by committee and instead constructing a camel. (32) A month later, the government went to the same U.S. magistrate judge with the same request but, this time buttressing its application with an affidavit. The court concluded that this did nothing to change its view. (33)

The Impact of CALEA on the Government's Request

One of the most important matters CALEA addressed was law enforcement's continued access to the fast-changing telecommunications infrastructure for the purpose of conducting lawful electronic surveillance. With the emergence of wireless technology, law enforcement did not want to be in a worse situation when attempting to engage in such surveillance than it was when telephony was accomplished only through copper wires. (34) Providers, thus, are required by CALEA to ensure that their deploying technologies permit the same electronic surveillance access as before while, at the same time, ensuring continuing safeguards against unwarranted privacy intrusions.

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Passage of the legislation, which guarantees continued access by law enforcement--given the advent of wireless technologies--to call-identifying information via pen registers, was ensured by inserting the restriction that in no event could such data "include any information that may disclose the physical location of the subscriber[.] (35) The U.S. magistrate judge in the District of Columbia case relied extensively on testimony before Congress of then FBI Director Freeh concerning privacy and the bill that ultimately became CALEA. The court found the director's statement compelling, stating

   The Director's offer and its acceptance by Congress led to the
   exception codified at 47 U.S.C. [section] 1002(a)(2) ... [T]he
   exception was based on the express representation by the government
   to Congress that the authority for pen registers and trap and trace
   devices would not and could not be used to secure location
   information, the very information the government wants to secure by
   using a pen register and trap and trace device. (36)

In a case in December 2005 in the Southern District of New York, the government was able to obtain location information. (37) However, while this decision was helpful, in reviewing this case it is important to bear in mind that the location information sought in this request was relatively imprecise (less intrusive) when compared with the more focused data at issue in the requests already discussed. In this case, the court granted the government's application seeking "information pertaining to the location of cell site towers receiving signal from a particular cellular telephone[,]" i.e., "cell site activations," (38) and requesting that the cell phone company provide a map detailing the locations of its cell towers, i.e., their "locations/addresses, sectors and orientations" to include "the physical address/location of all cellular towers in the specified market." (39) As might be expected given the differing call volumes, there are more towers in a given urban area than would be present in a rural area of the same size. This means that the towers will be closer to each other in the city than in outlying areas. Therefore, the closeness of the towers will help determine more precisely the location of an operating cell phone.

The U.S. magistrate judge emphasized the importance of the less exact types of information sought in the request before him than in the requests for orders previously discussed, stating

   First, the cell site information provided in this District is tied
   only to telephone calls actually made or received by the telephone
   user. Thus, no data is provided as to the location of the cell phone
   when no call is in progress. Second, at any given moment, data is
   provided only as to a single cell tower with which the cell phone is
   communicating. Thus, no data is provided which could be
   "triangulated" to permit the precise location of the cell phone
   user. Third, the data is not obtained by the Government directly
   [from the user's phone] but it is instead transmitted from the
   provider digitally to a computer maintained by the Government. (40)

The government again relied upon the pen register and trap and trace statutes and section 2703 in its request. The court echoed observations made in the earlier cell phone tracking decisions, agreeing that "the Pen Register Statute would by itself provide authority for the order being sought by the Government were it not for [47 U.S.C. [section] 1002]." (41) The court seized upon language in CALEA providing that subscriber physical location information may not be "acquired solely pursuant" to the pen/trap statute. The court reasoned that there is "simply impose[d] upon law enforcement an authorization requirement different from that minimally necessary for use of pen registers and trap and trace devices." (42) In attempting to resolve what this authorization may consist of, the court considered the government's argument that section 2703(c) may provide the solution. This provision, along with 2703(d), permits the government to petition for an order upon a showing of specific and articulable facts establishing reasonable grounds to believe that the contents of a communication or the records or other information sought are relevant and material to an ongoing criminal investigation. The U.S. magistrate judge concluded that "cell site or tracking information comes within section 2703(c) and consequently is the sort of 'information' that the Government may seek pursuant to an order under section 2703(d)." (43)

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The next issue to confront the U.S. magistrate judge was whether section 2703 provided authority to obtain prospective information. Indeed, chapter 121 of the U.S. Code, Title 18, of which 2703 is a part, is captioned "Stored Wire and Electronic Communications and Transactional Records Access," (44) thus suggesting that its provisions relate to acquired or historical data. The court dismissed this contention, relying on the notion that cell site location information "is transmitted to the Government only after it has come into the possession of the cellular telephone provider in the form of a record." (45)

Not surprisingly, the uncertainty continues. A ruling on another request from the government was issued by a U.S. magistrate judge in the Eastern District of Wisconsin who rejected the government's request for prospective information. (46) The court's primary concern was with the CALEA caveat discussed earlier limiting access to information disclosing the physical location of the subscriber when sought through a pen register or trap and trace device. In the court's view, this proved insurmountable.

In yet another ruling in January 2006, a U.S. magistrate judge in the Western District of Louisiana allowed the government to acquire some limited cell site information stating "the Government will know only that the user has made or received a call on his cell phone, and that his cell phone communicated with a particular tower or towers during the call [, thus,] ... no Fourth Amendment concerns are implicated." (47)

Conclusion

The only thing certain with respect to the legal requirements for acquisition of cell site information by the government for purposes of identifying the location of a cellular telephone and its user is that nothing is certain at this moment. The path that the use of cell site tracking is headed down is likely toward a legislative solution. In the interim, law enforcement should track judicial developments closely within their jurisdictions. State and local law enforcement also should take a proactive role with respect to legislative solutions to this uncertainty within their own state electronic surveillance statutes.

Law enforcement officers of other than federal jurisdiction who are interested in this article should consult their legal advisors. Some police procedures ruled permissible under federal constitutional law are of questionable legality under state law or are not permitted at all.

Endnotes

(1) Even government-owned tracking devices are undergoing modernization in the 21st century, moving from radio tracking devices to those using the more precise global positioning satellite system (GPS). GPS tracking by law enforcement has been upheld on the same basis as the older, more traditional, radio-based tracking equipment, United States v. Moran, 349 F.Supp.2d 425 (N.D.N.Y. 2005). Note, however that today "the traditional homing devices ... are now monitored via radio signals using the same cell phone towers used to transmit cell site data." In the Matter of the Application of the United States of America for an Order Authorizing the Installation and Use of a Pen Register and a Caller Identification System on Telephone Numbers [sealed] and [sealed] and the Production of Real Time Cell Site Information, 402 F.Supp.2d 597, 604 (D.Md. 2005) (hereafter DMD).

(2) 460 U.S. 276 (1983).

(3) 468 U.S. 705 (1984).

(4) "A person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements from one place to another .... [The subject] voluntarily conveyed to anyone who wanted to look the fact that he was traveling over particular roads in a particular direction, the fact of whatever stops he made, and the fact of his final destination when he exited from public roads onto private property." Knotts, supra note 2 at 281-282.

(5) [N]otions of physical trespass based on the law of real property [are] not dispositive ...." Id. at 285.

(6) Probable cause to monitor will be required if electronic tracking is to occur "within a private dwelling," i.e., a "location not open to visual surveillance." Karo, supra note 3 at 714-715.

(7) It is submitted that for other than stored, previously acquired cell site location data, "real-time" and "prospective cell site information" are conceptually the same thing: permission is being sought to obtain "yet-to-be" information that is to be acquired/become available during a span of time that is to occur after an authorizing court order would be signed. However, one court has suggested that the two terms can mean different things. DMD supra note 1 at 599.

(8) 355 F.3d 942 (6th Cir.), cert. denied, 543 U.S. 856 (2004).

(9) 18 U.S.C. [section] 2510 et seq.

(10) Forest supra note 8 at 947.

(11) DEA "used Sprint's computer data to determine which cellular transmission towers were being 'hit' by the [target's] phone. This 'cell site data' revealed the general locations of [the target]." Id.

(12) Id. at 950-951. "Although the DEA agents were not able to maintain visual contact with [the target's] car at all times, visual observation was possible by any member of the public. The DEA simply used the cell site data to 'augment the sensory faculties bestowed upon them by birth,' which is permissible under Knotts .... [T]he cell site data is simply a proxy for [the target's] visually observable location." Id at 951. (original emphasis).

(13) Pub.L.No. 99-508, 100 Stat. 1848 (1986). Note that 18 U.S.C. [section] 2701-2712 (Title II of the ECPA, as amended) is referred to sometimes informally as the Stored Communications Act (SCA) even though it is not denominated as such within the body of ECPA.

(14) Note that prior to passage of the USA PATRIOT Act of 2001, Pub.L.No. 107-56, 115 Stat. 272 (2001), 18 U.S.C. [section] 3127(3) defined pen register as a "device which records or decodes electronic or other impulses which identify the numbers dialed or otherwise transmitted on the telephone line to which such device is attached[.]" Prior to the advent of cell phones (when telephones were connected by copper wires), a pen register was actually a machine that printed onto a roll of paper all numbers dialed from the targeted phone. It also would print the times that the telephone receiver was picked up (off hook) and when it was replaced (on hook). Today, most of the data that the machines used to acquire and print out are collected and arranged by service provider computer feeds and software. "[Information that was heretofore captured by a pen register can now be transmitted digitally by the telephone service provider." SDNY, infra note 37 at 439 n. 1. In recognition of this technology shift, section 216 of the USA PATRIOT Act updated the pen register definition (and, relatedly, that of the trap and trace "device" as well) so that [section] 3127 (3) now describes a pen register as "a device or process which records or decodes dialing, routing, addressing, or signaling information transmitted by an instrument or facility from which a wire or electronic communication is transmitted[.]"

(15) In the Matter of an Application of the United States for an Order 1) Authorizing the Use of a Pen Register and a Trap and Trace Device and 2) Authorizing Release of Subscriber Information and/or Cell Site Information, 384 F.Supp.2d 562, 563 (E.D.N.Y. 2005) (hereafter EDNY #1).

(16) 18 U.S.C. [section] 2510 (12) (definition of electronic communication).

(17) Id.

(18) 18 U.S.C. [section] 3117(b).

(19) Supra note 15 at 564.

(20) Pub.L.No. 103-414, [section] 103, 108 Stat. 4279, 4280-81 (1994), codified at 47 U.S.C. [section] 1002(a)(2)(B).

(21) 47 U.S.C. [section][section] 1002(a)(2) and (a)(2)(B).

(22) Supra note 15 at 565. To the extent the government seeks a cell phone user's location based upon the pen/trap statute, this is correct. However, a strong argument exists that such information can be obtained from carriers based upon a less than probable cause order issued pursuant to Federal Rule of Criminal Produce 57 and the All Writs Act, 28 U.S.C. [section] 1651. 18 U.S.C. [section] 3117(a) states in pertinent part that "a court is empowered to issue a warant or other order for the installation of a mobile tracking device[.]"

(23) EDNY #1, upon reconsideration, 396 F.Supp.2d 294, 295 (hereafter EDNY #2). "Congress plainly intended the 'location' prohibition in CALEA to regulate not only what a carrier can provide, but also what law enforcement can lawfully 'obtain.'" EDNY #2 at 307, n. 9.

(24) In re Application for Pen Register and Trap/Trace Device with Cell Site Location Authority, 396 F.Supp.2d 747 (S.D.Tex. 2005) (hereafter SDTX).

(25) Id. at 749.

(26) Id.

(27) Id. at 749-750.

(28) Id. at 765.

(29) Supra note 1 at 600.

(30) Id. at 604.

(31) In the Matter of the Application of the United States of America for an Order Authorizing the Release of Prospective Cell Site Information, 407, F.Supp.2d. 132-133 (D.D.C. 2005).

(32) Id. at 133.

(33) In the Matter of the Application of the United States of America for an Order Authorizing the Release of Prospective Cell Site Information, 407 F.Supp.2d 134 (D.D.C. 2006) (hereafter DDC #2).

(34) "The purpose of [CALEA] is to preserve the government's ability, pursuant to court order or other lawful authorization, to intercept communications involving advanced technologies such as digital or wireless transmission modes ... while protecting the privacy of communications and without impeding the introduction of new technologies, features, and services." H.Rep. No. 103-827 (1994), at 9, reprinted in 1994 U.S.C.C.A.N. 3489.

(35) 47 U.S.C. [section] 1002(a)(2)(B).

(36) Supra note 33 at 138.

(37) In re Application of the United States of America for an Order for Disclosure of Telecommunications Records and Authorizing the Use of a Pen Register and Trap and Trace Device, 405 F.Supp.2d 435 (S.D.N.Y. 2005) (hereafter SDNY). See also In the Matter of the Application of the United States for an Order: 1) Authorizing the Installation and Use of a Pen Register and Trap and Trace Device; and 2) Authorizing Release of Subscriber Information and/or Cell Site Information, 411 F.Supp.2d 678, (W.D.La. 2006) (hereafter WDLA).

(38) "Cell site activations" refers to "cell site information concerning the physical location of the antenna towers associated with the beginning and termination of calls to and from a particular cellphone[,]" but not during the course of the call. SDNY supra note 37 at 437.

(39) Id.

(40) Id. at 438.

(41) Id. at 440.

(42) Id. at 443 (internal citations omitted).

(43) Id. at 445. In a friend of the court brief filed in the case, the Federal Defenders of New York, Inc., argued that such a 2703(d) order could not properly be issued because the statutory definition of electronic communication specifically excludes "any communication from a tracking device." 18 U.S.C. [section] 2510(12). This is the same argument which the EDNY magistrate judge found sufficiently compelling to be determinative. In SDNY, the magistrate judge deflected that contention: first, by recognizing that a cell phone user is a consumer of "electronic communication service" and, second, by acknowledging that such service includes a number of capabilities, i.e., a package that is more than just cell site information and, thus, information pertaining to a subscriber of that service is obtainable under section 2703(c). SDNY supra note 37 at 446.

(44) Emphasis supplied.

(45) SDNY supra note 37 at 447.

(46) In the Matter of the Application of the Unted States of America for an Order Authorizing the Disclosure of Prospective Cell Site Information, 412 F.Supp.2d 947 (E.D. Wis. 2006).

(47) WDLA supra note 37 at 682. Just before this article went to press, five more U.S. magistrate judge decisions relating to cell phone tracking were issued: In the Matter of the Application of the United States of America for an Order Authorizing the Installation and Use of a Pen Register and/or Trap and Trace for Mobile Identification Number [phone] and the Disclosure of Subscriber and Activity Information Under 18 U.S.C. [section] 2703, No. 06-MJ-506, 2006 WL 354289 (W.D.N.Y. Feb. 15, 2006); In the Matter of the Application of the United States of America for an Order Authorizing the Installation and Use of a Pen Register with Caller Identification Device and Cell Site Location Authority on Certain Cellular Telephone, No. MISC.2:06 MC 0028, 2006 WL 445922 (S.D.W.Va. Feb 17, 2006); In the Matter of the Application of the United States of America for Orders Authorizing the Installation and Use of Pen Registers and Caller Identification Devices on Telephone Numbers [Sealed] and [Sealed], Misc. No. 06-41, 2006 WL 462338 (D. Md. Feb. 27, 2006); In Re Application of the United States for an Order for Prospective Cell Site Location Information on a Certain Cellular Telephone. No. 06 CRIM, MISC. 01, 2006 WL 468300 (S.D.N.Y. Feb. 28, 2006); and In Re Application for an Order Authorizing the Installation and Use of a Pen Register Device, Trap and Trace Device, Dialed Number Interceptor, Number Search Device, and Caller Identification Service, and the Disclosure of Billing, Subscriber, and Air Time Information, No.S-06-SW-0041 (E.D. Cal. filed Mar. 15, 2006).

By M. WESLEY CLARK, J.D., LL.M.

Mr. Clark is a senior attorney in the Domestic Criminal Law Section, Office of Chief Counsel, DEA.