SafeHarbor are the eBay police department. If a buyer does something they’re not supposed to, then it’s SafeHarbor you should be reporting it to.
Non-paying Buyers.
This is the most common rule buyers break — it’s all too easy for them to just change their minds and try to get out of the auction. eBay, however, regard every auction as a contract. They will punish the buyer for you if they don’t go through with their end of the deal, by giving them a strike against their account. A buyer who doesnt consistently doesnt pay for items they win will probably get banned.
To report a non-paying buyer, you need to file an Unpaid Item dispute, which you can do here: http://feedback.ebay.com/ws/eBayISAPI.dll?CreateDispute. All you need is the item number. Once you do this, eBay will send the buyer a reminder that they must pay for the item they won, wait a while, and then take action against them. You must wait 7 days before you can file a dispute.
This isn’t that helpful to you, of course, since in most cases you still won’t get paid for the item or have anyone to post it to: it is a rare buyer who responds to...