Open flight information has in the past been used to track both the world's biggest illegal arms dealer Viktor Bout, and also the CIA rendition-to-torture flights.
Not really. I.e. they don't have to do something repugnant to want that information blocked. The military may not want to provide free intelligence about their forces to other nations. And "the wealthy" are pretty much at constant war with each other; tracking when a CEO leaves and where they go in order to gain advantage on the stock market is not unheard of.