Oh yeah there's that. Accepting payments for an adult site would certainly do it. What I don't understand is, how do PayPal find out about it? Random checks? Do PayPal, like Google, have an army of people randomly checking the referral URL's of PayPal buttons? Snitches? There is a section in the PayPal website's contact form for reporting violations... But how many people would bother to do that? Maybe competitors.
I'm wondering if it's ok to send payments below $0.5 "as a gift" so they won't take any fees. I've sent more than 100 so far and didn't have any problems but I'm not sure I'll risk this anymore. What do you guys think?