http://y7yea4pmqqtznb33qiugvysyn2bob5v62e4pvoadoibrwkq3tsddjeyd.onion/ps/module/facebook-groups-reducing-risks
Facebook groups were not designed for secure collaboration, but as the popularity of Facebook grows, they are inevitably used to coordinate work that may be vulnerable to sabotage or surveillance by other Facebook users, governments, and, of course, Facebook itself.