If you go to the top of this page and over to the left....place your curser over the green in the far left column and a sight menu will pop out that has "chat room" as an option.
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 .