Are leaks accidental or did someone poke a hole in the bucket.

As my life as a gamer goes by, I come to think of times where so called leaked gameplay, or leaked release dates, are not leaks, they are just publicity stunts. I have heard a lot of things in my years of gaming; Gear of War this, Halo 3 that. But when I come to think of it, how can someone actually run a phone-in room when it’s supposed to be “top secret”. If it was supposed to be top secret, wouldn’t they confiscate your phones and mp3 players at the entrance? While I don’t mind leaks, it’s when it becomes obvious that it’s more than that that gets me mad. When someone has acquired a release date, or details about a game, how did they acquire such knowledge? It seems to me that leaks are just an excuse to get some attention just like someone we all know. I am sure that some content is considered leaked but I am also positive that publishers “LEAK” information to the public.