Not a subscriber, a sometimes advertiser. It should be clear by now, that for whatever reason, they don't intend to fix the problems with the forums. I agree though that they should just let people know.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .