Just FYI for anyone using Facebook for organizing purposes, I have had my ability to send 'friend' requests blocked.
No one complained, but each morning I made a habit of sending requests to ten (10) people, all of whom being people I shared at least 100 'friends' with. I should have tracked how may days I did that, but my guess is something like 20.
This is yet another example of the problems you can run into whilst using Facebook in your union work.
More HERE. Even though the article is somewhat dated, the problems persist.