You can detect them with older mobile hotspots with a chip capable of promiscuous mode. Right now mine’s just a canary, a heads up that someone is operating an IMSI catcher nearby, but if ICE is active in your neighborhood having something like that but with more range could be useful for community early warning networks.

It’s funny when you complain to the police about this type of behavior from police neighbors and their families.

The police will start with calling mental health services on you.