Have you noticed some well-known tech accessory makers disappearing from Amazon? Those aren’t just rare incidents — they’re part of a larger campaign. In a response to The Verge, Amazon has confirmed a South China Morning Postreport that the internet giant has banned over 600 Chinese brands (spread across 3,000 seller accounts) over review fraud incidents. These firms intentionally and repeatedly violated review policies banning incentivized reviews, Amazon said.

The online retailer first broke word of the figure in an interview with VP Cindy Tai on the state-controlled network China Central Television. It had previously kept relatively quiet on the broader effort.

The crackdown began in earnest five months earlier, but it received wider attention when Amazon banned Aukey and Mpow. The venders were caught offering rewards, including gift cards, for customers leaving reviews. Amazon later booted RAVPower, Vava and other relatively well-known brands for similar behavior. It’s not clear how many non-Chinese brands have faced bans.

There are signs these vendors are either dodging bans or have otherwise escaped some detection, such as Aukey earbuds under the Key Series brand. However, it’s safe to say the wider anti-fraud strategy has significantly changed Amazon’s marketplace — much to the chagrin of banned companies that heavily depended on Amazon-based sales.