celebrities fair game

So are celebrities fair game do we photographers have the right to follow these people everywhere and photograph anything they do. Me personally I don't care what they do that just me but from a photographers point of view they are fair game as long it doesn't go to far like evading their privacy. But if there outside getting coffee I can follow them to their car as long its a public place so I say YES. Sadly to say they are public figures in our society as that we can follow them to certain extent and photograph them. But their is a line that we photographers I think don't cross thats we don't photograph them while evading their privacy thats my opinion I will never trespass on their property go in a helicopter and photograph them in their home. I will never be aggresive shooting while their children are around. So photograph them but don't take it to far okay people.