If you’re using an Android device—or in some cases an iPhone—the Telegram messenger makes it easy for hackers to find your precise location when you enable a feature that allows users to find others who are geographically close. The researcher who discovered the disclosure vulnerability and privately reported it to Telegram developers said the company has expressed no plans to fix it.

The problem stems from a feature called People Nearby. By default, it’s turned off. When users enable it, their geographic distance is shown to other people who have it turned on and are in (or are spoofing) the same geographic region. When People Nearby is used as designed, it’s a useful feature with few if any privacy concerns. After all, a notification that someone is 1 kilometer or 600 meters away still leaves stalkers guessing where, precisely, you are.

Stalking made simple