Alarmed by the use of hard-to-track prepaid cell phones by terror suspects, New York Sen. Charles Schumer and Texas Sen. John Cornyn have introduced legislation requiring consumers to produce identification before buying such phones.
The bill has been praised by law enforcement and has bipartisan support, even as civil liberties groups have raised privacy concerns and some terror experts say it won't deter bad behavior.
Prepaid phones can be a lifeline for people with limited incomes or poor credit, allowing them to purchase a device and a limited amount of calling time without committing to a costly contract.
Phone companies sold $16 billion worth of prepaid cell phones last year, and the devices are hugely popular.
But since the phones can be purchased anonymously and are thrown away after use, they've long been a favored tool of drug dealers, gang members and even white-collar criminals looking to cover their tracks.
In recent years, such phones also have been linked to suspected terror activity - including that by Faisal Shahzad, the Pakistani-American accused of plotting to bomb Times Square. Law enforcement officials said Shahzad had used a prepaid cell phone to communicate with co-conspirators in Pakistan.
A handful of states and several countries require registration to purchase a prepaid cell phone. In an interview, Schumer said the Shahzad case, combined with the growing use of prepaid cell phones in criminal cases, had persuaded him that federal regulation was needed.