Two key senators want to know if the leader of the vast U.S. intelligence apparatus believes it’s legal for spooks to track where you go through your iPhone.

In a letter that Sens. Mark Udall of Colorado and Ron Wyden of Oregon will send later on Thursday, obtained by Danger Room, the senators ask Director of National Intelligence James Clapper, “Do government agencies have the authority to collect the geolocation information of American citizens for intelligence purposes?”

Both senators are members of the panel overseeing the 16 intelligence agencies. In May, they sounded warnings that the Obama administration was secretly reinterpreting the Patriot Act to allow a broader amount of domestic surveillance than it had publicly disclosed.

“[R]ecent advances in geolocation technology have made it increasingly easy to secretly track the movements and whereabouts of individual Americans on an ongoing, 24/7 basis,” they write. “Law enforcement agencies have relied on a variety of different methods to conduct this sort of electronic surveillance, including the acquisition of cell phone mobility data from communications companies as well as the use of tracking devices covertly installed by the law enforcement agencies themselves.”

Geolocation is a particular interest of Wyden’s. Technically, there are few obstacles to clandestine geodata collection, since most smartphones feature built-in GPS. So along with a House Republican, Jason Chaffetz, Wyden introduced a bill that would require warrants for law enforcement to collect geodata. As our sister blog Threat Level has reported, a patchwork of inconsistent recent court rulings has yet to resolve whether geolocation data is protected by the Fourth Amendment.

But intelligence collection is a horse of a different color. The 2008 FISA Amendments Act that blessed the Bush administration’s warrantless surveillance programs allowed intelligence agencies greater leeway to collect metadata on Americans’ communications abroad. It’s unclear to the senators if that or any other law prompted the spy community to move into geolocation collection.

That’s why Wyden and Udall want “unclassified answers” from Clapper. If Clapper thinks his spies can go after U.S. citizens’ geodata, they want the “specific statutory basis” for that collection, along with a description of any “judicial review or approval by particular officials” that might accompany it. They also want to know if Clapper thinks there’s any affirmative legal “prohibition” to geodata collection by spies, if the spy chief doesn’t think it’s legal.

The senators note that legislative restrictions on GPS acquisition so far only apply to cops and feds, not spies. “Clearly Congress needs to also understand how intelligence authorities are being interpreted as it begins to consider legislation on this issue,” they write.

They also remind Clapper that the FISA Amendments Act is set to expire at the end of the year. The letter asks Clapper to disclose if the surveillance dragnet it authorizes includes the communications of “law-abiding Americans,” the key objection from civil libertarians to the Act, and if any “significant interpretations of the FISA Amendments Act [are] currently classified.”

That’s the “secret law” fear that vexes Udall and Wyden. And if it applies to the Patriot Act and geolocation collection, it might also apply to more traditional avenues of government surveillance.

Photo: Flickr/ForestAndKim