You're getting hung up on the "access" part, it's the "authorization" that's important. In your example it would likely be almost impossible for the blog owner

You're getting hung up on the "access" part, it's the "authorization" that's important. In your example it would likely be almost impossible for the blog owner to prove that someone intent on posting negative comments was not authorized to do so. As a side note, I think we all should be more careful with "omg, we're losing our freedoms!" comments. They're usually not as clever as they feel at the time, and have the dangerous property of inuring us to such claims.