The MIB lore is less about actual interaction with 'aliens' and more about men in black suits who drive big black American cars (and unmarked helicopters, I guess) who threaten UFO experiencers to keep them quiet, confiscate evidence of UFOs and generally cover up the whole phenomenon. IRL there are a number of witnesses who talk about Air Force Intelligence officers confiscating the hard drives containing the radar data from the famous "tic-tac" UFO encounter on the Navy ship USS Nimitz. Lots of other witnesses for AF Intelligence doing stuff like this, including disinformation campaigns, so maybe they are the real MIB.