He sells a product on the internet. He has been having the chronic refunder issue popping up for himself with his CB products. He has put together a system which generates a unique single pixel image per client. When they refund they receive a letter stating they are to delete the product as per his TOS. If the server detects a hit to that image after 72 hours a C&D letter is generated and sent. If they are a US,UK or AU client and the pixel is again hit after 48 hours from the previous hit, a notification is sent to attorneys he has on staff in the localities he can pursue them.
So far he has 9 small claims or civil suits in play. He has won a judgement in 5 of them which include a minimum of 2500$ in damages per case and in Australia and Europe includes criminal charges for theft and software piracy. He sent the results to his list and that day about 15% of his list unsubscribed. His refund rate is now in the 2-3% range.
There are ways to fight back.