How much should employers know? Pocket your privacy by understanding the limits of background checks.

Whether you're in the running for a job as a mailroom clerk or a corporate officer, pre-employment screenings have become commonplace.

With all this probing into your background--via national databases, court records and telephone interviews--what are your rights as a prospective employee, and how can you protect your privacy while cooperating with an employer's request for information?

Because of the benefits and training costs associated with a new hire, employers usually conduct background checks when they are seriously considering a candidate, says Dannette Evans, president of EMDM , Information Consultants in Marietta, Georgia. According to Evans, of companies that conduct pre-employment screening, 81% verify education; 79% check previous employment, 59% check references; 37% examine criminal records; 50% conduct drug testing and 21% inspect motor vehicle records. Twenty percent check nothing at all, adds Evans. It's also not uncommon for employers to investigate credit reports, current and previous residences, identity (Social Security number, etc.), workmen's compensation and civil records in each jurisdiction of residence and, in some rare instances, even conduct genetic testing.

The first step is to educate yourself on the issues that fall within the legal and illegal realms of the pre-employment screening process, advises Rebecca Locketz, legal director for the American Civil Liberties Union's Workplace Rights Project in Princeton, New Jersey. Investigations concerning marital status and age are considered illegal The Americans with Disabilities Act makes medical investigations illegal unless the applicant has been offered a job and, even then, an employer's decision cannot be based on a disability. The Employee Polygraph Protection Act prohibits the use of lie detector tests as a condition of employment. In many states, employers cannot deny employment based on an arrest record that has not resulted in a conviction.

Locketz also recommends reading the fine print on applications, particularly the waiver agreement that gives a prospective employer permission to delve into your background. The wording in these documents, she adds, often relinquishes what little rights the employee already has.

In most instances, an employer needs your written consent to begin a background check--submitting a resume does not constitute authorization. If you don't feel comfortable with the terminology used in the waiver agreement, Locketz advises that you have the right to edit the waiver or seek clarification as long as you have the agreement of the prospective employer.

Be forewarned that the Fair Credit Reporting Act identifies employment as a just reason for an employer to check your credit. Generally, potential employees who will work with large sums of money are prime candidates for credit checks. So to eliminate surprises, order your credit report regularly to ensure all information reported is accurate. If you are denied employment because of your credit history, an employer is obligated under law to provide you with a copy of your report or the name of the agency that generated it.

But why all this probing? One reason is because we have a competitive job market and employers want to get the best applicants, says Ethan Winning, author of Labor Pains: Employer and Employee Rights and Obligations (Winning Associates Inc., $29.95; 800-823-366). Another reason is the increase in workplace violence, he adds.

The Negligent Hiring Doctrine--on the books in 28 out of 50 states--holds employers responsible for checking the background and references of job applicants who come in frequent contact with the public. This doctrine protects employees when an employer has not screened, let's say, a violent employee properly and the well-being of other employees is jeopardized. But, warns Locketz, it also allows employers to delve even deeper into an employee's background.

If you think you're a Likely candidate for extensive pre-employment screening, you may want to check your own background--beyond ordering your credit report--before you begin a job search. That way you will know how your references, employment history, etc., check out. The process can cost $30-$200, depending on the type of information you need. Check your phone book under employment screenings for companies providing this service.

From the employer's perspective, background checks safeguard both the company's bottom line and its employees. Says Evans, "It's Like a double-edged sword. You want to protect employees' rights as much as possible, but companies have to protect themselves also."