my guess would have been paypal, marked as "friends and family"
because quite frankly, 90% of the people who get "scammed" played the part of the willing victim by lying to paypal and claiming friends and family
as for the complaining part, i dont really see the point of a one sided "warning" on a side hes not part of
first of, because he doesnt get a chance to explain himself, and secondly, because chances are we'll never meet this fellow anyway
(even though we live in the same area code)
but mostly because i would like to hear why it wasnt his fault
