Basant Gajjar used “cloaking”, a technique that hides the true content of ads and presents something different on the surface for users on the platform, which prevented Facebook’s review process from identifying improper ads, the company said.

Advertisers were able to promote links for deceptive diet pills, cryptocurrency scams, and even misinformation about the coronavirus outbreak through the technique, Facebook added.

Gajjar’s unregistered business in California, LeadCloak, has been offering cloaking services since 2016, targeting firms including Alphabet Inc’s Google, Oath, WordPress and Shopify Inc, Facebook said.

Reuters could not immediately reach Gajjar for a comment.

The lawsuit was filed in the US district court in the Northern District of California, San Francisco division.