Five companies sued eBay, the American Numismatic Association (ANA) and the Professional Numismatists Guild Inc. in January for defamation and unfair and deceptive trade practices. The complaint states that in September 2007, eBay put into place a policy in which only coins that have been graded by four grading services (NGC, PCGS, ICG and ANACS) may be listed for sale on eBay as "certified" coins, referring to all other coins as "counterfeit."
The plaintiffs claim that the ANA announced the new eBay "Counterfeit Currency and Stamps policy" in a September 18, 2007, press release, and say eBay has publicly accused plaintiffs of grading and/or dealing in counterfeit items. As a result, plaintiffs say, they "have been injured in their respective abilities to carry out their professions, trades, and occupations and have been exposed to distrust, hatred, contempt and ridicule."
http://docs.justia.com/cases/federal/district-courts/florida/flmdce/6:2008cv00042/209017/1