In 2016, David Jarrett, a student at Rowan University, suffered first-, second-, and third-degree burns after a portable phone combusted in his pocket, according to a complaint filed in New Jersey federal court. In 2017, the lithium-ion battery that Kyle Melone had bought for his vape pen on Amazon exploded in his pocket, setting his shorts and leg on fire; he ended up in the intensive-care unit, according to a complaint filed in Rhode Island federal court. Exploding lithium-ion batteries have caused hoverboards to catch fire and houses to burn down; Bentley told me his clients include a man who lost an eye, another who burned his genitals, and one who experienced “massive brain injury.”

The link among many of these dangerous products is Amazon, where the world shops. More than half of the items sold on Amazon are listed by third-party sellers—not by Amazon itself—which makes ensuring that products are safe and authentic difficult, according to Juozas Kaziukenas, the founder of Marketplace Pulse, a firm that researches Amazon. In the case of batteries, batches of lithium-ion cells made in China that don’t pass inspection sometimes end up listed by sellers on Amazon, said Michael Rohwer, a director of Business for Social Responsibility, a nonprofit that works with companies on their supply-chain practices.

In a statement, an Amazon spokesperson said, “Safety is important to Amazon and we want customers to shop with confidence on our stores. Third-party sellers are required to comply with all relevant laws and regulations when listing items for sale in our stores. When sellers don’t comply with our terms, we work quickly to take action on behalf of customers.”

Read: Amazon may have a counterfeit problem

Insurance companies have even started to sue both Amazon and battery makers because they say they’ve had to pay out many claims over lithium-ion-battery explosions. Allstate New Jersey Insurance sued Amazon in U.S. District Court in New Jersey, alleging that a battery bought on Amazon caused “extensive” damage to a home, which required the insurance company to make “significant payments” to the insured. That case was eventually dismissed, but both State Farm and General Insurance Company of America are currently suing Amazon because of fires they say were caused by lithium-ion batteries purchased on the platform. (Amazon declined to discuss any of these specific cases, but has denied the allegations in court filings, saying it was not the seller of these products.)

Even as the fires keep happening, battery manufacturers, Amazon, and consumers are all blaming one another. But so far, courts have pinned the blame neither on Amazon nor on the battery manufacturers. This is because websites such as Amazon can argue in court that they are merely a platform that allows buyers and sellers to connect. Unlike, say, Macy’s, which buys products wholesale and resells them to consumers, Amazon often doesn’t own or even touch the products bought and sold on its site—so in Amazon’s view, it’s not liable for defective products. In its response to David Jarrett’s legal complaint, the company said in a court filing that his alleged injuries “were caused by acts or omissions of third-persons or entities over which Amazon has no control.” And it’s easy for third-party retailers to disappear after selling a defective or dangerous product, even if they pop up a few weeks later under a different name and address, again selling dangerous products.