The Federal Trade Commission on Monday sued Amazon, alleging the e-commerce giant “secretly and systematically overcharged” advertisers on its platform by manipulating its pricing and auction systems.

The lawsuit, which was joined by 22 state attorneys general, argues that Amazon may have reaped more than $20 billion from advertisers by using “hidden surcharges” dating back to a change to its auction rules that took effect in 2019.

The complaint, which was filed in U.S. District Court for the Western District of Washington, centers on Amazon’s sponsored products ads, brands ads and display ads that run alongside search results on its sprawling webstore.

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