Is that different than any other form of media though? You could make the same argument for news and politics contained within newspaper publications, radio, and television.
I think the Internet is different because not everyone has access to a studio and a satellite dish, or print and deliver enough newspaper across across a country as well as a government could. But most people have access to a phone, laptop or just an old dial up connection. But unlike other mediums, the Internet is directly traceable. If a rebel is posting to twitter, Facebook, or some other social website, anyone can trace it, not only to the person who posted it, but to people who "liked it", shared it, and retweeted it and potentially giving up the position of sympathesizers to a rebel cause.