It was off-campus. How do they have the right to do that?
Its a Jesuit school, they probably have to agree to follow the student code of conduct even off campus, similar to the people that attend Liberty University.
Really all this situation shows is that people shouldn't put so much information on facebook or the internet in general. I mean I comfortable with people being able to find my name online, but other than that there is not much information people can find on me. Even at my school, which is public, students can get in trouble for having pictures of themselves drinking on facebook, which is why my lacrosse team has a no camera/picture policy at all our parties.
Moral of the story is don't be stupid online and you can have all the douchebag themed parties you like.