De Ceukelaire has discovered Vulnerability-related.DiscoverVulnerability that he can exploit Facebook to obtain cell phone numbers of users ; which they want to remain hidden . According to De Ceukelaire , he can easily identify the cell phone numbers of well-known personalities including top politicians and “ Flemish ” celebs simply through checking out their Facebook profile . This is done by analyzing the numbers that are associated with their profiles . It must be noted that these numbers are supposed to be confidential information and aren ’ t viewable by the public . Must Read : Hacking Facebook Account by Knowing Account Phone Number Reportedly , De Ceukelaire proved his claim Vulnerability-related.DiscoverVulnerability by obtaining the cell number of Jan Jambon , the Interior Minister for Belgium , through his Facebook profile . He further stated that : “ For clarity , I could find out his number on his account , not vice versa ; roughly , I think you get the number 20 percent of the Flemish people can find that way . Of all the people who have their mobile number linked to their profile goes to the 80 percent ” . De Ceukelaire already warned Vulnerability-related.DiscoverVulnerability the Facebook security team twice about this issue and stated that he might expose it to the public if the social network does not fix Vulnerability-related.PatchVulnerability the issue and make necessary changes . However , according to Facebook ’ s representatives , this isn ’ t a vulnerability that has been exploited Vulnerability-related.DiscoverVulnerability but a feature . He also notified law enforcement authorities about the exploitable aspect of this feature . “ If the users enter their private phone numbers and don ’ t lock them down in the privacy settings section , chances of a privacy leak are quite bright ” . Facebook informed De Ceukelaire about how to control the searching criteria , that is , who can search for you through your phone number or email address but De Ceukelaire asserts that this is a privacy leak because phone numbers are visible to the public while these are supposed to remain confidential . This problem was identified way back in 2012 because the cell number ’ s setting could not be set to visible by “ Only Me ” . Facebook did make Vulnerability-related.PatchVulnerability some modifications in its privacy settings feature , due to which only a limited number of reverse lookups would come from a particular IP address . This happened after a security researcher managed to access thousands of random phone numbers . But , it is apparent that the problem hasn ’ t been fixed Vulnerability-related.PatchVulnerability even today . It is worth noting that De Ceukelaire didn ’ t release details about how he managed to exploit Facebook to conduct this privacy leak and whether he used any different method than previous security researchers or not . But , yet again Facebook is paying no heed to his pleas of getting this feature fixed and he has been given the same ‘ Feature not Flaw ’ reply this time as well