They were flying over military installations, if they were anyone else's drones, they would have been shot down like the weather balloons that spook the government from time to time.
I've seen the reaction to people flying their toy drones too close to military assets, they send men out with machine guns and megaphones, confiscate the drone and sometimes press charges.
Maybe the US reacts differently, but in Europe most military bases have been scouted by Russian drones, and afaik none were shot down.