Since prepaid cell phones don't require a contract, credit check or identification to purchase them, they are one of the last remaining anonymous communication tools.

Used by the poor, reporters, their sources, whistleblowers, abused spouses and anyone needing an untraceable phone number, they've also become the device du jour of drug dealers and terrorists who want to avoid the eyes and ears of law enforcement. While such phones pose problems for police agencies -- they can't be wiretapped as can traditional cell phones and land lines -- their purposes are far-reaching.

But this safety net or criminal-enabling device -- depending on one's perspective -- may be eliminated if a newly introduced Senate bill passes. A bipartisan pair of Senate leaders recently introduced legislation that would require prepaid cell phone purchasers to present identification and cell phone companies to keep that information on file for 18 months after the phone's deactivation.

"Although there are many legitimate users of prepaid cell phones, they have also become the communication device of choice for terrorists, drug lords and gang members interested in masking their identities," stated a press release from Sen. Charles E. Schumer, D-N.Y. "Since they can be purchased and activated without signing a contract or undergoing a credit check, prepaid cell phones provide virtual anonymity."

This anonymity has been highlighted in such popular TV shows as HBO's The Wire and NBC's Law & Order, in which criminals exploit this virtual mask to communicate. Fiction aside, they've been used to coordinate terrorist plots, like the recent attempted attack on New York's Times Square, in which 30-year-old suspect Faisal Shahzad allegedly purchased a Nissan Pathfinder and tried to turn it into a mobile bomb. He apparently used a prepaid cell phone to coordinate the purchase of the vehicle, as well as make a series of calls to Pakistan days prior to the attempted attack.

This certainly isn't a new trend, Schumer noted in the press release. The 9/11 hijackers used prepaid cell phones to communicate in the months leading up to the attack, he stated, and the devices were used as detonation devices in the 2004 Madrid train attack.

In a 2002 speech by FBI Director Robert Mueller, he cited the 9/11 plotters' use of prepaid cell phones to illustrate how they "managed to exploit loopholes and vulnerabilities in our systems, to stay out of sight, and to not let anyone know what they were up to beyond a very closed circle."

And criminal communications via prepaid cell phones isn't just for terrorists and drug dealers. Wall Street executives and hedge fund managers implicated in a 2009 insider trading bust used prepaid cell phones to avoid potential wiretaps, with one suspect allegedly having chewed a SIM card until it snapped in half to destroy possible evidence.

"While most Americans use prepaid mobile devices lawfully, the anonymous nature of these devices gives too much cover to individuals looking to use them for deviant, dangerous means," Sen. John Cornyn, R-TX, stated in a press release. "It would be foolish to stand idly by while the risk remains that another terrorist or criminal could purchase a prepaid phone leaving no paper trail."

But as privacy advocates point out, that anonymity is a precious refuge in an age where nearly all communication can be traced back to its source. "There needs to be a broader appreciation of prepaid services, both the value of prepaid services in general and the value of anonymity," said Center for Democracy and Technology Public Policy Vice President Jim Dempsey. "It's important that we have certain safety valves in society where not everything is traceable and not everything is identifiable."

There's also the undeniable fact that criminals will find ways around

Karen Wilkinson  |  Staff Writer