You can find just about anything you want on eBay, from duct tape to Kim Kardashian's old clothes. It's a magical place! It's also an online retailer violating its own rules, and helping buyers sidestep California law, because you can easily buy and sell assault weapons parts on the website.
No need for DIY assault weapon enthusiasts to go to specialty shops: There's plenty of gun parts for sale on Ebay. Simply by digging around on the site, Reveal found listings for nearly every part of a semi-automatic AR-15 readily available. There's only one gun part not accounted for on eBay: the lower receiver, which is regulated. But someone can assemble everything else and then build their own receiver, or buy one privately.
Now, Ebay has tools it uses to flag and ban content that violates its terms and breaks the law. The company uses keyword filters to pull up suspicious items, and people can flag stuff as well. But it's obviously not working. Savvy sellers make a point not to explicitly mention assault rifle compatibility when they sell parts meant to be used with the rifles, for instance. Others, like a seller called "AR15 Solutions", don't even bother.
This isn't a problem limited to Ebay. Basically any big platform where people gather can become a marketplace for items that break the law and violate terms of service. Instagram and Facebook have received criticism from anti-gun lobbies for their failure to keep gun sales off the services, for instance.
It's probably impossible to keep gun sales and gun part sales offline completely. Even if large e-commerce platforms manage to actually figure out better ways to kick off gun sellers, there's always black markets like The Armory. But Ebay is an enormous retailer with plenty of resources, and it's solutions so far have come up laughably short. Why not hire a team to manually trawl and flag for potential gun-parts sellers?
Well, Ebay does take a cut of every sale, whether or not it's a sale that violates its terms or the law. So unless pressure gets placed on the company to take a more proactive approach to stopping these gun part and accessory sales, there's not much to gain from truly cracking down.