Facebook security prevented a former employee of Cambridge Analytica from entering its New York headquarters for a happy hour last week, raising questions about the scope of the social media giant’s security blacklist and its policy toward people associated with the infamous data firm.

According to Robert Murtfeld, formerly the director of commercial sales for Cambridge Analytica, Facebook security guards took him aside last Thursday evening after he filled out his name in a digital check-in kiosk in the lobby of the company’s offices at 770 Broadway. The guards informed Murtfeld’s host, a communications executive at Facebook, that Murtfeld wouldn’t be allowed inside. Murtfeld, who did not know the host and told BuzzFeed News that he had never previously been inside any Facebook office, had been invited to the happy hour by a mutual friend who does not work at the company.

“My host said to me, ‘I don’t know what you’ve done in your private life, but you’re not allowed into this building,’” Murtfeld told BuzzFeed News.

It was likely Murtfeld’s public life that raised Facebook’s alarm. Murtfeld believes he was banned due to his association with Cambridge Analytica. It is unclear if that is correct, and if so whether the ban would extend to all of the political consulting firm’s employees - or its clients.

Facebook did not respond to multiple requests for comment for this story.

In 2018, the Observer and the New York Times reported that Cambridge Analytica inappropriately harvested personal information about tens of millions of US citizens through access to Facebook’s API. The revelation prompted intense scrutiny of Facebook’s data practices, as well as the role Cambridge Analytica - founded by billionaire Robert Mercer and former Breitbart executive and White House adviser Steve Bannon (who schemed to plant a mole at Facebook) - played in the 2016 US presidential election. The firm shut down in 2018, but Facebook has been repeatedly forced over the past two years to answer questions about the way third parties can use the platform’s scale and targeted advertising apparatus to influence voters.

Unlike the Cambridge Analytica whistleblowers Christopher Wylie and Brittany Kaiser, and the company’s former CEO, Alexander Nix, Murtfeld has not sought the spotlight. According to Murtfeld, his work at the data firm predominantly consisted of pitching corporations and political parties on the company’s services. A story last month in South Africa’s Sunday Times described an email sent from Murtfeld to Kaiser on Oct. 11, 2015, that “compiled a list of upcoming elections that could be targeted.” Murtfeld, who is now director of business development for a golf resort in New Jersey, told BuzzFeed News that his work never involved direct contact with Facebook.

Last year, CNBC reported on Facebook’s secretive 12-year-old “BOLO” — or “be on lookout” — list, a directory of hundreds of people whom Facebook’s security team considers a threat to the company and its employees. The story describes a similar incident to the one last week, in which an invited visitor was screened in the lobby of Facebook’s Menlo Park campus and temporarily prevented from entering. (The host eventually intervened with Facebook security and had the visitor removed from the “BOLO” list.)

The CNBC report focused primarily on individuals who had made menacing comments on Facebook. But Murtfeld’s rejection suggests that former Cambridge Analytica employees are also banned from the company’s offices. (Facebook has suspended the personal accounts of several people associated with Cambridge Analytica, including Wylie.) It also raises the broader possibility that Facebook’s list of personae non gratae is larger than previously thought, extending to entire corporations.

“I’m not a security threat,” Murtfeld said. “I thought the whole thing was outrageous.”