Facebook monitors and tracks the locations of its users when the company’s security team finds that they are making credible threats on its social network, according to a report from CNBC today.

The company actively monitors its platform for threatening comments, the report said. That can include a nonspecific threat to a Facebook location or a direct one targeted at specific people. Once Facebook determines that a threat from a user is credible, the company uses data from its products to track that person’s location.

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According to CNBC, this is done by using location data taken from the user’s Facebook app or an IP address collected by the social network when a user is active on the Facebook.com. CNBC reported that the locations of users are only accessible after they’re placed on a “Be On the Lookout” (BOLO) list after their threats are deemed credible. But it’s unclear exactly who determines what is a credible threat or what criteria a threat has to meet to be deemed credible.

Other platforms use similar techniques to track threats, but CNBC reported that they typically do not have access to real-time location and other key data. Security employees at Facebook can use Facebook’s own product to identify and track anyone it believes to be a threat.

Vague threats like ‘Fuck you, Mark Zuckerberg’ also have the potential to be used as a reason to track a user

Specific threats of violence can land a user on the BOLO list. But more vague complaints, such as “Fuck you, Mark Zuckerberg,” could be used as a reason to track a user as well, the report said. The user is not notified that they have been placed on the list.

There are other options once someone is deemed a risk as well. According to CNBC, Facebook’s security teams can call in extra guards or contact law enforcement.

“Our physical security team exists to keep Facebook employees safe,” a Facebook spokesman said in a statement to CNBC. “They use industry-standard measures to assess and address credible threats of violence against our employees and our company, and refer these threats to law enforcement when necessary. We have strict processes designed to protect people’s privacy and adhere to all data privacy laws and Facebook’s terms of service. Any suggestion our onsite physical security team has overstepped is absolutely false.”

In one instance, Facebook used this technology to catch a group of interns who said they were working from home but were actually out on a camping trip. A Facebook employee made the case that the company just wanted to make sure they were safe. Reportedly, location data didn’t turn up anything of value, so Facebook security employees went through the interns’ messages. By going through those private messages, the security employees were able to determine that the interns never planned to go into work that day.