The US Supreme Court had outlawed the FBI's use of GPS trackers. The FBI complied by shutting down all its devices but now is apparently having trouble actually retrieving the hardware. Because the GPS units are turned off. And the FBI has no idea where they are unless they're on.
The Court ruled in US v Jones that the Federal Bureau use of unwarranted vehicle-based GPS tracking units was illegal on the grounds that the practice violated the 4th Amendment -- specifically that the act represented a search and constituted trespassing. The FBI complied and nixed its 3000 currently active GPS tracking devices but that's where the problem lies.
Turns out the FBI can't locate the devices unless they're active. The Agency so determined to retrieve its toys that it has petitioned the court to briefly turn the devices back on for the sole purpose of finding and retrieving the hardware. I bet they wish they'd just bothered with those warrants now.
Top art: AP