Unless telecommunications providers follow a lengthy list of eavesdropping requirements for calls made aloft, the FBI and Homeland Security don't want.
In a letter to the Federal Communications Commission sent last Thursday, the police agencies said any rule permitting "in-flight personal wireless telephone use must consider public safety and national security" concerns.
At the moment, technical and social reasons keep cell phones muted during flight: Few passengers relish the prospect of sharing a row of seats with a yappy fellow traveler. Also, concerns about overwhelmed cellular towers and interference with avionics systems have resulted in the current prohibitions.
The FCC is considering proposals to relax those restrictions. One possibility, for instance, would be to permit "pico cells" inside a commercial airliner that would create a cabin-wide hot spot for voice and Internet links.
The FBI and Homeland Security say that the 1994 Communications Assistance for Law Enforcement Act, or CALEA, requires that airlines follow strict wiretapping guidelines. The police agencies, for instance, want to be able to eavesdrop on conversations no "more than 10 minutes" after the call is made.
"There is a short window of opportunity in which action can be taken to thwart a suicidal terrorist hijacking or remedy other crisis situations onboard an aircraft, and law enforcement needs to maximize its ability to respond to these potentially lethal situations," the agencies say in their letter.
Other requirements the FBI and Homeland Security are requesting that the FCC mandate include: identifying the seat number of the passenger making the call, making sure police can "expeditiously interrupt" a conversation, cut off service to all passengers except government agents on a plane, and so on.
"That's not what Congress had in mind when they wrote the statute," said Kurt Opsahl, a staff attorney at the Electronic Frontier Foundation, a civil liberties group in San Francisco.
Opsahl called the police agencies' request a "wish list" that extends far beyond what CALEA requires. "If the FBI succeeds in this context, what's to stop them from getting more wiretapping powers than they currently do in other contexts?"