I watched this documentary last night - covers a few sports. I will point out that the claims have not been proven, but the show is in line with this discussion:
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 .