A buzzy TV series based on the book “An Ugly Truth: Inside Facebook’s Battle for Domination” is currently in the works — but the social media giant is now warning the production company behind the project for “recklessly” proceeding with development of a “false and defamatory” adaptation.

In a legal letter sent on Monday, high-powered attorney Mathew Rosengart, who is repping Facebook, puts Anonymous Content on notice with an email addressed to CEO Dawn Olmstead.

“Facebook obviously recognizes that it is a public figure and has great respect for the First Amendment and the right of journalists and film or television producers to publish stories about it,” the letter, obtained by Variety, reads, in part. “The First Amendment does not protect knowingly false statements or portrayals — or those made with reckless disregard for the truth — even about public figures.”

The letter says that Facebook might consider working with Anonymous Content on ensuring the TV project is “accurate and truthful,” though it states that the book puts Facebook and its leaders under a “false light,” in violation of California law, so should the screenplay mirror the book’s “false statements, characterizations and implications,” Facebook will take legal action.

“An Ugly Truth,” authored by New York Times reporters Sheera Frenkel and Cecilia Kang, gives the investigative reporters’ account of the scandals and toxic culture at the social media giant. Published this past summer, the book became an instant New York Times best seller.

Anonymous Content’s series, titled “Doomsday Machine,” has cast “The Crown” star Claire Foy as Facebook COO Sheryl Sandberg. The drama is described as focusing on Sandberg (Foy) and Zuckerberg (yet to be cast), who are responsible for shaping the way that billions of people worldwide communicate and consume information, as Facebook has navigated political and social trenches in its quest for growth. Based on Frenkel and Kang’s book, plus reporting by The New Yorker‘s Andrew Marantz, Ayad Akhtar is creator of the television adaptation. Anonymous Content (“Mr. Robot”) will produce the series with Wiip (“Mare of Easttown”).

Rosengart, a shareholder at Greenberg Traurig, has objected to claims in the book such as the assertion that Mark Zuckerberg “struck a deal” with former President Trump to adopt a new policy for his “political speech.” In the letter, Rosengart writes: “To be clear, there was no ‘deal’ with Donald Trump, and you (and others associated with this series) are on the notice of this fact.” The lawyer also takes issue with the book stating Zuckerberg “sought to elevate ‘company over country,'” which the lawyer calls “a grossly misleading characterization.”

If Rosengart’s name sounds familiar, it’s because Facebook is the latest high-profile client for the Hollywood power player, whose name has been praised around town for representing Britney Spears in her legal battle over her controversial conservatorship. Ever since the pop star was given the right to hire her own attorney this past summer and began working with Rosengart, more movement has taken place than over the past 13 years, and her path to freedom has become clear. Prior to Spears retaining Rosengart, the former federal prosecutor had worked with figures including Sean Penn, Steven Spielberg, Julia Louis-Dreyfus, Keanu Reeves and Pearl Jam’s Eddie Vedder.

Spears’ millions of fans around the globe have been applauding Rosengart in his successful efforts to get the singer’s father, Jamie Spears, suspended from the conservatorship. After the suspension in late September, Spears’ father obtained new counsel as he gears up for a fight against Rosengart, whose firm has pledged to fully investigate him for accusations of financial mismanagement and conservatorship abuse. Rosengart is now gearing up for the pop star’s next hearing at the Los Angeles Superior Court on Nov. 12, which is when her conservatorship is expected to be terminated by Judge Brenda Penny.

As for Facebook, Rosengart’s legal letter on Monday warns Anonymous Content that the company “cannot immunize” itself from legal liability by relying on the book or the New York Times’ reporting, which, the attorney says, contains the “false and disparaging statements” that are “actionable as defamation.”

Anonymous Content did not immediately respond to Variety‘s request for comment on this story.