Sen. Al Franken (D-Minn.) wants the Justice Department to hand over any information it might have about law enforcement agencies getting their hands on location data from cell phone companies.

Earlier in the year, the U.S. Supreme Court ruled in a case, United States v. Jones, that law enforcement agencies needed to first obtain warrants before using GPS devices to track people. In that case, the justices said law enforcement could not install tracking devices without a warrant, because that fell into the definition of a "search."

But in a letter yesterday to Attorney General Eric Holder (PDF), Franken pointed to recent news reports suggesting that state and local law enforcement agencies "may be working around the protections" set down by the courts.

"I am eager to learn about how frequently the Department requests location information and what legal standard the Department believes it must meet to obtain it," he wrote. Franken's position seemingly puts him at odds with the Obama administration -- as well as law enforcement agencies -- which have taken a harder line on using location data to track people. Before the recent Supreme Court ruling, the DOJ told a federal appeals court that the FBI as well as other police agencies don't need to obtain a search warrant to find out the locations of Americans' cell phones.

In his letter to Holder, Franken asked for the following: