Tiffany & Company is going to court against eBay, alleging that the online auction service allows sellers to list counterfeit Tiffany jewelry. The suit also alleges that eBay makes millions of dollars in fees from the auction of counterfeits.

Tiffany bought several hundred items on eBay, all listed as “Tiffany”. 75% of those items were found to be fakes.

EBay’s defense is that the company merely brings together sellers and buyers, and that the company is not responsible for the authenticity of items. The case is considered very serious, as a loss for eBay would open the door for ever other brand that believes fakes are being sold on the auction site.

One research analyst has suggested that Tiffany is pursuing this case in order to stop “secondary” sales of its products. If eBay is no longer an option, buyers will be more likely to buy directly from Tiffany.