Buyer beware! It appears that POTN does not allow users to leave negative feedback. If you would judge a transactions safety by feedback it appears that you'll be unable to find evidence of a bad transaction so the feedback system is not what you think it is! That's only a rumor so far. I've heard it's the policy and am now checking it out. If it's false, I'll delete this. I don't even know where to look yet, but that's disturbing if it's true since buyers should be able to receive warning from fellow users (not POTN admin) if they're dealing with a demonstrated scammer on POTN. I'm trying to find out.
EDIT: I haven't found any info about it in any of the FAQ's, rules, etc. that I've read. If it's true I'd have no way to know it (and neither would any other POTN member who is looking for the info) so I doubt it's true. Surely POTN wouldn't prohibit other users from warning each other about a scamming seller. I'll have to see if I can figure out how to contact a mod without using the "emergency" system (as that seems to be against the rules) to see if I can get a direct answer or if they have or will create a part of a FAQ that addresses the issue in some way.