Because the devices aren't illegal, and have legal uses, but eBay is being held responsible for the illegal ways end users use these devices.
The only real violation that might have occurred here is not removing listings for these devices where they are explicitly marketed for illegal purposes. Short that, they need to actually justify passing a law outlawing these devices, or they need to enforce the existing laws against deceptive use of these devices.
AFAICT it is up to the EPA whether or not to exempt noncompliant nonroad engines/equipment that are intended solely for competition. I don't think you need to explicitly market a product for illegal purposes for the EPA to determine that it is not unlikely to be used contrary to the intent.
> New nonroad engines/equipment you produce that are used solely for competition are excluded from emission standards. We may exempt (rather than exclude) new nonroad engines/equipment you produce that you intend to be used solely for competition, where we determine that such engines/equipment are unlikely to be used contrary to your intent.
Is that different from any other retail store that has to choose what products to carry based on the local laws? Just because eBay crowd sources their product acquisition, doesn't materially change the fact that they are, ultimately, a retailer selling products. I go to a store and buy a product, and the only difference is in the retailer's perception of my relationship to the origin of the product, but it's a distinction that only exists on paper and ultimately has no difference from the outside. That distinction without a difference shouldn't create a loophole to bypass all liability.
