When a government institution or another controlling body yielding great influence coerces a media outlet into censoring something, even though that's not required by law, then I also consider that censorship. As such, I clearly consider the case of Wikileaks to be an example of a modern censorship attempt.

However, I also believe that the liberty of the press has to go both ways. A company should be free to deny the publishing of something, after all you can just start your own newspaper, or your own web engine that indexes content in this case, or whatever. It's not like your life is threatened, you just have to move your ass off your couch.