i'm not sure if photographers have access to it, but when i worked for a large newspaper group we had a programme that you could search someones address on just the name. We could even serach for all the John's in the uk!! (but you just wouldn't - you'd mess up the system). I don't know, maybe they have something like that??
We called it Compass and the intention was to verify addresses given to you by advertisers. Have a hunt for it!
I know several journalists they are mainly tipped off by the celebs themselves or they get a flunkie to do it and then pretend they didnt know about it.