As you probably know, the intelligence community (which is partly military) is not supposed to target U.S. citizens, but there is a fair argument that so-called

As you probably know, the intelligence community (which is partly military) is not supposed to target U.S. citizens, but there is a fair argument that so-called “incidental collection” of communications between a foreign target and someone in the US still amounts to “domestic spying”. However, for things like a spy drone where there’s no ambiguity in which jurisdiction is being targeted, I do think that no branch of the US military subject to the Posse Comitatus Act (all but the Coast Guard and, when called in, the National Guard) does or will use them on US soil. That said, civilian law enforcement agencies including the FBI, Border Patrol, DEA, and state police may do so. They all already use normal drones for various purposes.