Earlier this month, the FBI revealed that the suspected Times Square bomber had used an anonymous prepaid cell phone to purchase the Nissan Pathfinder and M-88 fireworks used in the bomb attempt. The case sparked new calls to regulate prepaid cell phones in order to provide more accountability and make the devices less attractive to criminals. Yesterday, Congress responded.

Senators Charles Schumer (D-NY) and John Cornyn (R-TX) joined forces and announced a new bill that would require an ID at the point of sale. Phone companies would need to keep this information on file in order to help police thwart "terrorists, drug lords and gang members," along with the occasional hedge fund manager.

"In 2009," said the Schumer/Cornyn announcement, "[prepaid cell phones] were even used by hedge fund managers and Wall Street executives implicated in the largest insider trading bust in US history. In court papers, federal prosecutors detailed how traders from the Galleon Group hedge fund communicated with other executives through prepaid phones in order to try to evade potential wiretaps. In one instance, one suspect is described as having chewed the Subscriber Identity Module, or SIM card, until it snapped in half in order to destroy possible evidence."

"We caught a break in catching the Times Square terrorist, but usually a prepaid cell phone is a dead end for law enforcement. There’s no reason why it should still be this easy for terror plotters to cover their tracks," said Schumer.

Prepaid phones can be bought over the counter in many different stores, from big-box retailers to gas stations, and many can be activated without credit checks or ID.

Some countries have already forbidden this sort of anonymous use. The Canadian government funded a study on this question back in 2006. A team from Simon Fraser University looked at 24 OECD countries and found that nine of them require mobile operators to collect registration data for prepaid phone users.

"In all cases, the rationale for a prepaid registration requirement was to improve efficiency of law enforcement and national security activities," said the report.

US states have followed suit; similar laws have been introduced in Texas, Massachusetts, Pennsylvania, Missouri, Georgia and South Carolina, according to Schumer and Cornyn. But "in light of the increased reliance of terrorists on the devices," the senators said, "it was time for a federal response."