A sandvich party is considered griefing which is against the rules since it means that you are refusing to help your team move up. So, I would warn the griefers, and if they persist, a ban will be issued; now depending on how many previous bans they've had on the servers and how often they play on the servers, I would adjust the ban lengths accordingly.
Posting another persons facebook is not against the rules only if the person allows the player to post it. But I'm assuming that he received no consent to post the "private" info. That would be against the rules, and I would gag him/her/them. Now, if I felt like the situation was serious enough, the poster would warrant a ban in my opinion.