Facebook knew a key ad metric was 'inflated and misleading' for years, lawsuit alleges

Facebook allegedly gave its advertisers "inflated and misleading" metrics on how many people their ads could reach for years, according to newly revealed court documents in a long-running lawsuit against the company.

The documents, unsealed on Wednesday by the US District Court for the Northern District of California, cite emails from a Facebook employee saying the company received "revenue we should have never made given the fact it's based on wrong data." The lawsuit alleges that the problems with the metric, known as potential reach, were "largely due to fake and duplicate accounts," but Facebook chose not to remove those accounts.