You know that old adage, that something is only as strong as its weakest link? Well, private Facebook groups are only as private as the admins keep them. Which means that all it takes is for one admin to accidentally (or intentionally) make the group public for a period of time, during which people who aren’t members of the closed Facebook group can see both the members, and what they posted. So how safe is it to rely on the private, closed status of a Facebook group? Not very, it turns out.