You'd call either. Just like if there is other suspected illegal activity, you contact the branch of gov't that handles it and not involve yourself. If you see

You'd call either. Just like if there is other suspected illegal activity, you contact the branch of gov't that handles it and not involve yourself. If you see someone speeding, it's not legal to speed to catch them. You call the cops and let them deal with it. Personally I don't see this working at all, or at least won't have much of an effect. Most drone pilots aren't sitting there for hours in the same place waiting to get caught, especially if they are knowingly doing something bad. They usually fly for 15-30 minutes and go somewhere else. By the time the cops/faa get to you, the drone, pilot and all their "remote id" data are long gone. In a lot of major US cities, cops aren't even responding to anything but the most serious of crimes due to budget cuts and personnel shortages. I don't see how they will even have the time to follow up given the list of priorities they have, maybe unless the report included a weapon mounted on the drone (which has happened). And people intent on breaking the law just won't register or get a drone with Remote ID anyway. They'd build their own (it's a fun hobby and how all this drone stuff got started to begin with - the first ones just used arduinos with appropriate sensors [see ardupilot project]) or use some of the millions already in existence built in the last 15 years that don't have the capability.