Easy money.

Internet phone calls and cheap, nearly anonymous wire transfers-money-saving propositions for people in the developing world--are turning into moneymaking tools for a small band of tech-savvy thieves in Latin America. In a twist on the well-known Nigerian e-mail scam, fraudsters in Costa Rica are charged with using a telephone trick to goad greedy U.S. citizens into sending money for a fake contest.

The newest scam involves using a technology called voice over Internet protocol, or VoIP. Twenty-four people were arrested in a joint U.S.-Costa Rican law enforcement effort that took three years to complete. The ring allegedly stole nearly US$20 million from more than 2,000 people in North Carolina and Florida by working from call centers created just for this kind of fraud.

Using the Web, the thieves were able to appear to be calling from a U.S. federal agency. The calls registered as originating within the United States, from Washington, D.C. Marks were told they had won a sweepstakes in a foreign country. To get the money, all they had to do was send $1,000 or more to a business in Costa Rica. The front money, the con men said, was an insurance fee and would be returned along with the prize. Anybody who sent cash, of course, never heard from the caller again.

"What people have to do is recognize when something is too good to be true," says Jason Gialanella, senior special agent with the U.S. Department of Homeland Security, which worked on the investigation. The agency has been tracking all kinds of Internet fraud of late, but the use of Internet phone systems was new. "The bad guys are aware that new technologies mean it will take time for the authorities to discover them," says Gialanella.