Hacker exploits a hole in the “Who’s Been Here” section of Foursquare’s website. Jesseper Andersen was able to scrape 70% of all check-in data in the San Francisco area over the last three weeks. The hacker says he’s been “trying to be white-hat” about his find, but he worries that users won’t know to seek it out in the first place. The site responded by adding a setting to opt out of the relevant section.”]
Source: https://gizmodo.com/foursquare-privacy-hole-leaks-nearly-a-million-check-in-5576799