RENEE MONTAGNE, host:
People with smartphones may notice the GPS technology. It shows you exactly where you are. Federal investigators have noticed the possibilities here. They've been placing GPS devices on the cars of drug or terror suspects. The question is whether they can track people without a warrant. The practice recently received a burst of publicity in California.
We begin with Mina Kim from member station KQED.
MINA KIM: When Yasir Afifi took his car in for an oil change, his mechanic found an unusual wire hanging from below. It was part of a black rectangular device attached to his car by a magnet. After posting photos of it online, Afifi, a Santa Clara college student and computer salesman, got a visit from FBI agents demanding their equipment back.
He's not doing new interviews now, but here's what Afifi told local television station KGO.
YASIR AFIFI: Where's the device that you located under your vehicle? And then I didn't even answer that. I just asked him: did you guys put it there? And then he goes: yeah.
KIM: The FBI confirms the device belongs to them, and that agents visited Afifi to get it back. But Special Agent Joseph Schadler won't say why it was there.
Mr. JOSEPH SCHADLER (FBI) It is not our policy to confirm or deny the existence of an investigation anyway, and we don't comment on sources or techniques or methods or anything like that.
KIM: The FBI sees GPS as an electronic version of physical surveillance used to gather information for an investigation.
Another Northern California man says the same thing happened to him. Abdo Alwareeth found a GPS device on his car two years ago while taking an auto maintenance class.
At his home in San Rafael, he sifts through a binder of papers he's gathered trying to understand why he was targeted. The U.S. citizen from Yemen says in all his 40 years living here, he's received nothing more than a traffic ticket.
Mr. ABDO ALWAREETH: Why I been singled out? Let them tell me, we are singling you out because you are an Arab and a Muslim and that's it. That's what I want to know.
KIM: Alwareeth says in his case local police came to claim the device. He's filed complaints and consulted lawyers. The police department's only response has been that it can't comment on the incident because the device doesn't belong to them. Now he and his wife check under their cars every day for tracking devices.
Mr. ALWAREETH: This is how they make us feel, that we are being tracked. Tracked for what?
KIM: It's unclear what legal remedies the two men have. In January, the 9th U.S. Circuit Court of Appeals ruled it's permissible for law enforcement to attach GPS devices to vehicles without search warrants.
Zahra Billoo is head of the Bay Area chapter of the Council on American-Islamic Relations and the attorney for Yasir Afifi. She says the FBI has violated her client's privacy rights. She says Afifi has nothing in his background to suggest he's a national security threat.
Ms. ZAHRA BILLOO (Council on American-Islamic Relations) If this is how our very limited resources are being spent, on these escapades targeting innocent individuals, I would say we are none the safer.
KIM: Billoo says the FBI is frightening the very community it claims it wants to build bridges with. But the FBI maintains in law enforcement keeping tabs on people is an essential part of the job. The question is whether GPS is too intrusive.
For NPR News, I'm Mina Kim in San Francisco.