From The Hill:

It’s been weeks since the Department of Justice announced that it was overhauling its rules for devices that simulate cell towers to prevent them from being used without a warrant. Now, congressional critics have a new target in their sights: the Department of Homeland Security. Senate Judiciary Chairman Chuck Grassley (R-Iowa) and ranking member Patrick Leahy (D-Vt.) sent a letter to Secretary of Homeland Security Jeh Johnson asking that new rules regarding the devices, called Stingrays, include a requirement that DHS agents get a warrant to use them.