Just to clarify my comments, I contact EVERY member (multiple times!) and give them chances to let me know they're still in before I give them the boot. But if it's the day of the group closing and I've been nagging you for two weeks with no response, then I'm not including you in the swap. And I would never post their name openly on the forum, I send PMs to other leaders of groups they're a part of to let them know someone dropped out on me so they can contact this person and see if they're still willing to participate in their particular swap as well. I'm not going to sit idly by while this person disappoints multiple members because "Oh well, my swap was taken care of." If you're going to flake out on me, I'm not going to allow you to do it to someone else, THAT was my point.

I don't mind having people say "I'm sorry, I joined the group but something happened, I have to drop out/I'm going to be late" that's COMPLETELY fine! But please, please, PLEASE let your group leader know if this happens ASAP!