This seems like a good way to get men in suits to show up at your door lol. Also the ultra-wealthy tech people are obsessed with privacy, you'd basically only know when he appears at public events. What do you want to use this for?
One of the projects I'm looking to create is a VR transportation tracker so I can go into VR and look at all the planes flying around the globe in realtime, watch shipping lanes, trains, etc.. Kind of a virtual command center you might see in a movie. Idk if I'll ever get around to doing it, but the place I was going to get plane tracking data was from here.
ADS-B Exchange - they offer unfiltered tracking data of planes. So if you happen to know what planes someone owns you could build a reasonable guesstimate of their movement.
And just for fun, here is the FCC Aircraft Registration Database Download . I don't know if this is the entirety of the database as there is a FCC blacklist of some sort for trackers which I'm trying to get my hands on to have a better idea of what planes out there are trying to operate under the radar, so to speak.
