On a side note, most of the posts I read on here are ancent, so I thought I might be able to revive some of them. Again, just posting my experience for someone else that might read this now 3yr old post!!
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 .