Telegram’s “people nearby” feature can be used to reveal a user’s precise location, according to bug-hunter Ahmed Hassan. The feature allows users of the secure messaging app to see who’s around them, however, it has been compromised by a severe security flaw. Hassan states that although you must enable the feature in settings as it is disabled by default, users who enable the feature are publishing their precise location unknowingly.

Hassan found that although it only tells you how far you are from another’s location, such as 1.3 miles, it’s possible to spoof one’s location for three different points and then combine the three distances to locate the user. Spoofing a GPS location is fairly easy, according to Hassan, who just walked around an area and collected the GPS latitude and longitude. There are also GPS spoofing apps that can be used to garner the same results. Telegram has not commented on Hassan’s findings.