https://arstechnica.com/tech-policy/2020/06/3m-sues-price-gougers-who-used-amazon-to-sell-masks-at-1800-markup/

3M—which manufactures N95 filtration masks that have been in high demand since the COVID-19 pandemic began—is suing merchants who used Amazon to sell 3M and counterfeit masks for more than 18 times their standard price.

A group of third-party merchants on Amazon "operated an illegal scheme to advertise and sell counterfeit, damaged, deficient, or otherwise altered respirators" to customers, 3M alleges in the complaint (PDF), filed in federal court in California.