Double posting to say be careful about the privacy settings if you use Firefox!!!!
I decided to add that one guy and make it so he couldn't really see any more than someone who is not a friend.
It didn't work when I followed all the directions for privacy settings when I was using Firefox. I found the help threads for Facebook and someone said they thought it was a glitch with Firefox and to try Safari or Internet Explorer. I tried it in IE and it worked, however the guy was still able to see stories posted to my wall and he can see the post stating I made a Catbook for my cat, even though I set that application to block him. I had to go application by application blocking this group. (I created a Farmville group before adding him.) He can now only see the pages I belong to, the posts for when I friend someone, and any Farmville stories or posts. I figured that was good enough, at least he can't see any status updates, notes, pictures, or personal information.
Just be careful and always double check!!!