In my experience, younger people are delightful and polite; it's the grannies and granddads you have to watch out for. They are so terrified by the Daily Mail and the television that even if you are stepping out of their way or holding a door open, they will not acknowledge you or say thank you!
I've seen some very rude bodhran playing in sessions. Some of them don't even ask if it's a non-bodhran room!
x ec