A group of advertisers filed a formal complaint Tuesday, alleging Facebook knew about problematic measurement tactics of video viewership and did nothing to address the problem for at least a year.

Tuesday’s complaint comes after a 2016 lawsuit against the company that alleges it engaged in fraud and deception by failing to disclose its faulty measurement system sooner.

Facebook acknowledged in September 2016 that it “found an error in the way [it] calculate[s] one of the video metrics” on its dashboard by excluding videos that were less than three seconds long to calculate “average duration of video viewed.”

That exclusion inflated reported average viewership times by 60 to 80 percent, according to Fortune.

Video ads are an important source of revenue for online publications that rely on advertising to generate profit. Video ad spending will account for roughly a quarter of U.S. digital ad spending in 2018, according to eMarketer.

Facebook will also capture nearly 25 percent of all U.S. video ad revenue in 2018, eMarketer reports.

Facebook’s video viewership numbers inspired news companies to move toward increased video production. ATTN, MTV News and other news companies reportedly fired writers and editors so they could “pivot” to video production, according to Adweek. Fox Sports cut down its digital writing and editing team reportedly in order to promote video content.

In their Tuesday complaint, the plaintiffs allege Facebook knew about the faulty measurements since January 2015 and did nothing. The plaintiffs also allege the company’s measurement tactic actually inflated video viewership times anywhere from 150 to 900 percent. Facebook “obfuscate[d] the fact that we screwed up the math,” the complaint reads, The Wall Street Journal reported Wednesday.

“Facebook’s internal efforts behind the scenes reflect a company mentality of reckless indifference toward the accuracy of its metrics,” the plaintiffs also said in their complaint.

If you missed it: today it was confirmed that Facebook massively & knowingly inflated its video-view statistics, which had the DIRECT consequence of 90% of media orgs firing writers in favor of expensive video producers, who also got fired when it turned out video was worthless https://t.co/WqdAUBIe6L

— Chris Conroy (@dyfl) October 17, 2018

“Suggestions that we in any way tried to hide this issue from our partners are false,” a Facebook spokeswoman said in a statement, according to TheWSJ. “We told our customers about the error when we discovered it — and updated our help center to explain the issue.”

“We are a political monoculture … quick to attack — often in mobs — anyone who presents a view that appears to be in opposition to left-leaning ideology,” Facebook engineer Brian Amerige wrote in an internal memo to the company from August. (RELATED: Former Facebook Engineer Rips Company Leaderships For Not ‘Pushing Back’ On ‘Social Justice’ Employees)

Amerige announced his resignation Oct. 10.

Facebook’s chief security officer Alex Stamos also left the company in March, reportedly over disagreements about how the company should deal with Russian disinformation spread through the social media outlet. (RELATED: Facebook Engineer Quits Over Company’s Mob-Like Attacks On Anyone Opposed To ‘Left-Leaning Ideology’)

“Facebook needs to lead with radical marketer and consumer transparency to get past this. We haven’t seen it yet,” Digital Content Next CEO Jason Kint said, according to TheWSJ.

Facebook did not respond to The Daily Caller News Foundation’s request for comment.

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