US Congressional lawmakers on Wednesday reintroduced legislation to establish rules limiting how American government agencies can obtain a person's whereabouts.

The Geolocation Privacy and Surveillance Act (GPS Act), sponsored by Sen. Ron Wyden (D-Ore.), Rep. Jason Chaffetz (R-Utah), and Rep. John Conyers, Jr. (D-Mich), was first introduced in 2011 during the 112th Congress (2011-2013). The bill didn't make it beyond the Judiciary Committee.

It was reintroduced during the 113th Congress (2013-2015), but again failed to advance through the legislative process. Another attempt was made during the 114th Congress (2015-2016), but the result was the same.

The 115th Congress will now consider the proposed legislation, or not, if history is any guide.

The GPS Act seeks to define when domestic law enforcement agencies can collect geolocation information about individuals without their knowledge, both through private companies and through cell-site simulators, also known as Stingrays or IMSI Catchers. It would also criminalize surreptitious use of electronic devices to track people's movements and would prohibit commercial service providers from sharing customers' geolocation data without customer consent.

Cell-site simulators are devices that masquerade as telecom company cell towers, in order to hijack communications flowing to and from nearby cell phones. The operator of the cell-site simulator – an authorized government agency or any rogue organization or individual in possession of one – can: calculate a phone user's location data through triangulation; collect device data like IMSI numbers and phone call metadata; eavesdrop on calls; spoof communications; and even distribute malware.

In security parlance, cell-site simulators represent a man-in-the-middle attack.

"Outdated laws shouldn’t be an excuse for open season on tracking Americans, and owning a smartphone or fitness tracker shouldn’t give the government a blank check to track your movements," Wyden said in a statement. "Law-enforcement should be able to use GPS data, but they need to get a warrant."

In a phone interview with The Register, an aide to Senator Wyden explained that changing circumstances suggest the bill may fare better than it has in the past, pointing to the passage of the USA Freedom Act in 2015 as a sign that there's broad support for reining in surveillance programs.

At the same time, Wyden's staffer suggested that the need for clear rules is even greater than it was previously. Digital tracking has become far more widespread than it was in 2011, the aide said, and it's also unclear that the Department of Justice will continue the Obama administration's policy of seeking warrants to track people through cell-site simulators.

US courts have yet to agree on when the government needs a warrant to track people through their cellphones or other devices. ®