"Scammer Warning" topics are classified as spam. They are trade forums and should be treated with the purpose with which they are intended - to trade. If somebody scammed, they'll have red tags underneath their name marking them as a scammer, else they're under review, or didn't scam. The team is great at getting scams taken care of, and they take scammer accusations quite seriously. However, a more common route is to put a "scammer list" or something of the sort in your profile/signature.
For future reference, questions can go here:
http://forums.d2jsp.org/forum.php?f=34