Your cellphone’s secret life

Opinion: May 11, 2012 at 12:00a.m.

Los Angeles Times: Concerned that mobile phone networks are becoming surveillance tools, the American Civil Liberties Union recently asked hundreds of local law enforcement agencies whether they’ve tracked people’s movements through their cellphones. Most of those that responded said they had, usually obtaining the information from mobile phone companies without a warrant.

The practice has become so routine, the ACLU found, that phone companies are sending out catalogs of monitoring services with detailed price lists to police agencies. The alarming findings should persuade Congress to clarify that the government can’t follow someone electronically without showing probable cause and obtaining a warrant.

The Supreme Court has long held that the Fourth Amendment guarantee against unreasonable searches and seizures requires police to obtain a warrant if the intrusion would violate a target’s “reasonable expectation of privacy.” That standard has barred law enforcement agents from surreptitiously recording what people say on the phone without a warrant, even when the conversation is taking place in a public phone booth. But the court and Congress set a significantly lower bar for monitoring other aspects of a phone’s use. Rather than trusting judges to sort it all out, Congress should make it clear that the protections that apply to phone conversations also apply to location data. No warrant, no tracking.