Personal things said in this room stay in this room.
Confidentiality is vital to a healthy discussion.
The only time it should be broken is when a group member reveals plans to harm himself or another person. Sarcasm and unkind remarks have no place in a discussion. If someone disagrees with another's comment, they should raise their hand and express their opinion of the comment, but not of the person who made it. It is permissible to attack ideas, but not each other. There is no such thing as a dumb question.