They're not requests, they're mandated by US law. Also it's not limited to rich and famous. Anyone can do it. Only the rich and famous seem to have passionate enough haters that they actively try to subvert the privacy protections.
AIUI it's mandated by US law if you use data from the FAA's system, and ADS-B Exchange didn't use the FAA's data so wasn't required to hide things on the privacy list