Violent protests rocked the Midwest city after the police shooting of Jacob Blake on Aug. 23. Blake was paralyzed in the shooting.
The suit, filed in the federal court of the Eastern District of Wisconsin on Tuesday, alleges Facebook failed to delete two pages on its platform that the lawsuit says encouraged violence against protesters. It claims this may have ultimately led 17-year-old Rittenhouse to allegedly kill two people and injure a third.
The complaint argues the "militia" groups the Kenosha Guard and the Boogaloo Bois broadcast a "call to arms" using Facebook, urging counter-protesters to fight those protesting the Blake shooting. Rittenhouse "answered the Call to Arms by driving across state lines from Antioch, Illinois with an assault rifle," the complaint states.
The plaintiffs said they were "terrorized, assaulted, harassed, and placed in so much fear when facing the business end of military grade assault rifles that they determined it was too dangerous to continue to protest," according to the complaint.
The lawsuit also argues that the deaths could have been prevented had Facebook taken action, saying the social media giant "received more than 400 warnings that what did happen was going to occur."
Facebook allegedly received hundreds of complaints and flags concerning the Kenosha Guard page, the complaint claims, "with reporters expressing that they were deeply concerned the Kenosha Guard was going out that night looking to intimidate and injure people protesting the shooting of Jacob Blake."
According to the complaint, it wasn't until days after the violence occurred that Facebook removed the Kenosha Guard page.
The lawsuit claims Facebook is enabling these so-called militia groups to recruit and conspire and that Facebook "continues to profit from their activities, and those who fight for social justice continue to die."
Rittenhouse is currently held in Illinois but faces charges in Wisconsin including homicide. His lawyers have previously argued via a produced video that he acted in self-defense, and the next court date for his extradition hearing to Wisconsin is set for Sept. 25.
"As to Kyle Rittenhouse, this lawsuit is errant nonsense but may provide a golden opportunity for obtaining documents and sworn testimony from Facebook to bolster Kyle’s future defamation case against Facebook for falsely accusing him of mass murder," Lin Wood, an attorney for Rittenhouse, told ABC News in a statement. "Thus, I view the lawsuit as a blessing in disguise."
A Facebook spokesperson told ABC News in a statement that the company "took action against organizations and content related to Kenosha."
"We have found no evidence that suggests the shooter followed the Kenosha Guard Page or that he was invited to the Event Page they organized," the statement added.
In an Aug. 28 video posted to Facebook, CEO Mark Zuckerberg said his company has made an "operational mistake" in not removing the Kenosha Guard page earlier.
Zuckerberg added that Facebook has designated the shooting as a mass murder and removed Rittenhouse's Facebook and Instagram accounts.
The other named defendants in the lawsuit include Kevin Mathewson, the operator of the Kenosha Guard Facebook page, and Ryan Balch, an alleged member of the Boogaloo Bois. Mathewson did not immediately respond to ABC News' request for comment. Balch could not immediately be reached for comment and phone numbers linked to him had been disconnected.