In yesterday’s decision in Tiffany v eBay, the Court noted:

Notwithstanding the significance of the online counterfeiting problem, it is clear that Tiffany invested relatviely modest resources to combat the problem. In fiscal year 2003, Tiffany budgeted approximately $763,000 to the issue, representing less than 0.05 percent of its net sales for that year .

From the decision:

First, the Court finds the eBay’s use of Tiffany’s trademarks in its advertising on its homepage, and in sponsored links purchased through Yahoo! and Google, is a protected nominative fair use of the marks.
Second, the Court finds that eBay is not liable for contributory trademark infringement . . . the standrard

WSJ.com Law Blog: Tiffany v. eBay:
“Who is responsible for the policing of counterfeit products on eBay?
If you think that’s an interesting question and you’re here in Gotham, hightail it down to Judge Richard Sullivan’s courtroom in the Southern District where a bench trial gets underway today pitting Tiffany against the online auctioneer.