I bet they don't bother with it. From their selfish point of view, they want to have as little friction as possible between the buyer thinking about it and paying. Speaking from my own experiences, I've definitely hesitated about buying something when I've had to physically pick up my wallet and get the card out - it's that psychological moment when the spending becomes real. Buying is just plain impossible if you don't have the card with you.
Ebay get their cut from each sale, and sellers stand the losses from fraud, so they gain from having as little security as possible. Any concerns are easily sorted with a few T&C changes.
These regulators seem to be doing their usual games of putting intentional loopholes in the rules, e.g. "If a firm can apply". They could just claim they can't because of (insert feeble excuse here). The regulator made a show of being concerned, nothing changed, everyone's happy.
They're up against Amazon, who I don't think have even checked the 3-digit code from the back of the card as that is not allowed to be stored, so if they asked for it they'd need the customer to have their card next to them. I don't know whether they check it when a new card is enrolled nowadays, they certainly didn't in the past. Again, presumably they've decided that the need to make buying simple outweighs the security advantage of checking it.
