The military is always going to exercise information control - I can't say I agree with it, but as far as I know they're well within their rights to do so and I can understand their reasons.
It's the private corporations thing that worries me a bit more. Where does it cross the line from being acceptable censorship to being unacceptable? It's all sort of a grey area, and I think this whole thing with Wikileaks is going to bring another big push for looking into this sort of thing as it relates to the internet.
The difficult thing is, where do you draw the line? For example, I think most people would consider moderation of a forum, a comments section or something of that nature run by a corporation or an individual to remove content that they don't agree with acceptable because people on the internet say dumb, inflammatory, racist and just plain wrong things all the time, as youtube comments show us. I also think most people would agree that, for example, if you had a website on hosting that was full of ridiculous racism or something of that nature the company providing you with the hosting would be within their rights to remove it. But what if what you're saying isn't illegal, isn't against the terms of service you signed but is just something someone else doesn't want you to say? I mean that's basically what has happened with Wikileaks, the US government doesn't want the documents published, and various companies are complying with this pressure.
I'm not gonna start the debate over whether that's right or not in here, there's already a thread for the whole Wikileaks thing, but where does that sort of censorship stop? What if a website has something on it that a politician or a celebrity just doesn't particularly like/want published? We already see this tactic used by the Church of Scientology to have negative content and websites taken down. I think it's a dangerous road to start down if organisations can get things taken off the internet just by applying a little pressure