Just my theory, of course, Bill, but from what I've observed in the Coins category, the crooks have been very active at times - no enforcement of some of the major rules about selling, in particular blatant violations of the Hobby Protection Act.
Some of those violations and the lack of enforcement would have been documented at
ebay, which must have made them worry about their liability, once they knew.
The RICO act was created to prosecute ongoing criminal activities (racketeers) and violations of the act; knowingly taking part in ongoing criminal activities triggers treble damages built into the law.
Even churches are being prosecuted under the RICO act, there's no reason to think
ebay would be immune. Transactions that cross state lines, involve the Post Office, or reach overseas also are triggers for enforcement.
Asian coin sellers provided a steady stream of unmarked counterfeit US silver dollars and trade dollars for years in violation of the Act with
ebay's knowledge, sold in bulk blatantly as unmarked admitted fakes at about $2 each, then resold again by the buyers, sometimes on
ebay as genuine coins for a lot more money.
The bad sellers of course made a lot of money but seriously contaminated the market, and now the fakers can afford much more sophisticated fakes, including faked slabs. It's a mess.
ADDED: I should've mentioned, counterfeiting has always singled out as one of the targets of the RICO act, so my guess is, since
ebay has often failed at enforcement, they no longer want to hear about it. Knowingly participating in the sales of counterfeit coins for profit should make any big business executive nervous.