In most cases they may have no recourse. A bunch of these made-for-Amazon brands are just a middleman in China selling white label products from an unspecified

In most cases they may have no recourse. A bunch of these made-for-Amazon brands are just a middleman in China selling white label products from an unspecified manufacturer. Oberdorf v. Amazon means that Amazon can be sued in Pennsylvania, but does not establish liability for other jurisdictions. The third-party seller is almost certainly liable, but they're a shell company in a country that is difficult for the legal systems of western countries to access. The manufacturer might have some liability, but it's difficult to establish exactly who that is, and they might reasonably claim that they're not selling a finished consumer product, so their only liability is to their customer the middleman. I think making Amazon liable probably is the best solution, but the courts haven't done it for most of the USA, and I doubt congress will.