I'm posting in the hope someone has some advice on what to do when there is a seller known to be operating a triangulation scam here on eBay.

For those unfamiliar, this is when the seller lists multiple items they don't have and can't genuinely supply, a buyer purchases from them and the seller purchases the item(s) from another seller and has it shipped directly. So, this part is basically dropshipping. The scam comes when CC chargebacks on the actual seller of the item, either they raise the chargebacks themselves or (probably more commonly) used stolen credit cards and the cardholders raise genuine chargebacks. 

The eBay buyers are obviously none the wiser in most cases, as they receive the items they purchased without issue, so getting eBay to do something about it has proven very difficult.

The seller in question has hundreds of listings - all stolen from various other eBay sellers / websites, and to add insult to injury (or more accurately, more injury to injury) if these other legit eBay sellers start getting a high number of chargebacks, it could mean more than just a financial loss on the orders they fulfilled, so time feels very of the essence here, and I would love some advice on what to do.

(Note: I am not one of the sellers this is happening to, but I want to help put a stop to it ASAP).