Are you people ACTUALLY serious that you would kick a team member off for drinking or doing drugs?
I can see if they are in the uniform or at a competition or something along those lines that there will be penalties, and if that leads to their removal from the team, then so be it, but to kick someone off because you found out they drank? Seriously? We're teenagers. Whether someone's a cheerleader or not, they're likely to experiment with alcohol, smoking, drugs, etc. and to punish them for something you most likely did at their age when it has NOTHING to do with the gym is absolutely stupid, and if I were an athlete there I'd leave the gym as soon as I found out about that policy. It's not just because of the drinking thing. If something I do has no relation AT ALL to my gym, that is my business and NOT the gym's.
Putting them on Facebook is the same thing. If they are not representing the gym in any way in that picture, I say they can keep it up. It's a reflection on themselves, not the gym. I think most people over think how much someone will look into a picture. If I see a picture of a drunk girl on Facebook, I don't look at her Facebook, find out where she works, and assume that that place is a terrible place because she's drunk and works there.