The trial court made four errors in granting Amazon judgment in this Prop. 65 action against it based on its listing (and sale) of 11 skin whiting products that contained mercury. First, it improperly found that tests of individual samples of the products didn’t prove that all of the product contained mercury. The test results showed mercury levels so high that it had to be an intentional ingredient not an accidental contaminant. And for Prop. 65 purposes, what mattered was whether the product contained any mercury, not the specific amount of mercury it contained. Second, the trial court erred in holding that plaintiff had to show Amazon had actual knowledge the product contained mercury. The decision holds that constructive knowledge is enough to hold a defendant liable. Third, the trial court was wrong in holding that plaintiff had to prove that purchasers of the product actually used it. Instead, Prop. 65 prohibits “exposing” consumers to cancer-causing chemicals absent required disclosures. A consumer is exposed to (laid open to the risk of) the chemicals when she buys the product, even if she ultimately doesn’t use it. Fourth, section 230 of the Communications Decency Act (47 USC 230) didn’t shield Amazon from liability because it was being held liable for its own failure to disclose exposure to cancer-causing chemicals, not for the advertising seller’s non-disclosure of the mercury contents of its skin-whiting creams.