Someone told me that in order to save dogs, rather than go to the pound they go to a puppy mill and buy up all the puppies. I thought that the idea was ridiculous when the shelters kill dogs every day but I do see how that strategy could work with ebay counterfeit denims.
Keep in mind that sometimes the sellers themselves don't know they have a fake.
Ebay may not remove every listing that is reported even if a bunch of people report it
But, if a person buys a pair of fake jeans advertised as genuine they get their money back 100% shipping round trip included.
After the transaction, you get to post a review on the seller, even power sellers will suffer with negative reviews.
As an extra security measure (but you don't really need it), do not use your PayPal balance to pay but put in your credit card. This is a double security as you get the ebay guarantee (that should work 99.9% of the time with fakes) and if that fails for any reason, you call your credit card company and dispute the charge saying they shipped you a fake. Paypal will treat the dispute in their regular way and resolve it according to their rules but if for some reason they side against you, they will give your money back as soon as they get the chargeback from the credit card company. Either way, the seller doesn't have a leg to stand on.
This is more work and hassle but it is risk free and will help eradicate sellers offering counterfeit jeans.
If you buy the jeans and return them, you hurt them where it counts because they have to pay for freight both ways and ebay keeps the commission. As the seller's reviews go south, they will stop selling those items...
So don't buy puppies from a mill but go all out on fake denim jeans.