Amazon has been cracking down on sellers and companies that manipulate reviews, either by posting fake reviews themselves, or by incentivizing buyers to leave reviews in exchange for gift cards or other rewards. Many companies have been barred from selling products on Amazon over the past few months, and now some of them are suing Amazon, claiming it is withholding their earnings.

Several companies based in China have filed a class-action complaint against Amazon (via The Verge), including Sopownic, Slaouwo, Deyixun, Cstech, Recoo Direct, Angelbliss, and Tudi. The action seeks the "recovery of funds that are being illegally and improperly withheld by Amazon" — in other words, income earned from Amazon sales that were not paid out before the companies were de-listed. Recoo Direct alone claims it is owed over $236,000, which sold accessories like webcams before being blocked.

Aukey and Mpow were among the first brands to be blocked by Amazon for fake reviews (at least during the current purge), back in May of this year. Amazon also removed RavPower from its store in June, and Choetech was banned in July. At the same time, Amazon forced Fakespot to be removed from the Apple App Store, which can help determine if a certain product has fake reviews or not. Fakespot is still available on the web and the Google Play Store.

The group of companies suing Amazon does not include high-profile tech brands, such as Aukey and Mpow, but they could join the class action in the future. Regardless, the lawsuit will test whether or not Amazon can (allegedly) withhold money from sellers that violated the company's rules.