Both sides of the political spectrum believe that their side is occasionally censored in the media--stories are just not reported for political reasons. I've never believed that to be the case. If there's a story, it will get out.
On the other hand, if a broadcasting entity offends a rich sponsor...that's a different ballgame.
Read this piece in the New Yorker to see a real life example.*
*Although, even in this case the New Yorker is reporting it...which means the story is getting out.
