From the ACLU website:
"Stingrays, also known as "cell site simulators" or "IMSI catchers," are invasive cell phone surveillance devices that mimic cell phone towers and send out signals to trick cell phones in the area into transmitting their locations and identifying information. When used to track a suspects cell phone, they also gather information about the phones of countless bystanders who happen to be nearby.Law enforcement agencies all over the country possess Stingrays, though their use is often shrouded in secrecy. The ACLU has uncovered evidence that federal and local law enforcement agencies are actively trying to conceal their use from public scrutiny, and we are continuing to push for transparency and reform."
The DRT Boxes are now being used in the air (plane, drone, helicopter, etc.) to sweep up even more information from cell phone users. It doesn't seem like there is even an expectation of privacy within the walls of your home anymore.