Istanbul, Feb. 15 () - Facebook, Inc. keeps a list of individuals who make threatening comments on the social network, according to a report by CNBC released on Thursday. When monitoring threats, Facebook complies a BOLO list ("be on lookout") which is updated once a week, while every time a new person is added to the last the company's security is sent a report about the individual. According to multiple sources with knowledge of the matter the outlet spoke with, the company's security team is able to track these individuals using location data from Facebook's apps. The people added to the list include those who write profanities in response to Chief Executive Officer Mark Zuckerberg's Facebook posts, one former employee said. Facebook picked up the threat, pulled the user's data and determined he was in the same country as the office he was targeting. The company informed the authorities about the threat and directed its security officers to be on the lookout for the user. "He made a veiled threat that 'Tomorrow everyone is going to pay' or something to that effect," a former Facebook security employee told CNBC. The incident is representative of the steps Facebook takes to keep its offices, executives and employees protected, according to more than a dozen former Facebook employees who spoke with CNBC. The company mines its social network for threatening comments, and in some cases uses its products to track the location of people it believes present a credible threat. One of the tools Facebook uses to monitor threats is a "be on lookout" or "BOLO" list, which is updated approximately once a week. The list was created in 2008, an early employee in Facebook's physical security group told CNBC. It now contains hundreds of people, according to four former Facebook security employees who have left the company since 2016. Facebook notifies its security professionals anytime a new person is added to the BOLO list, sending out a report that includes information about the person, such as their name, photo, their general location and a short description of why they were added.