|found on Invisible Bread|
One of the awful truths about the Internet is that you aren't the only one who gets to adjust your privacy settings. You need to occasionally re-check them because sites can and sometimes do revert the settings back to default, especially when there's a new feature they want you to try out (or just when they feel like it).
Unfortunately, privacy settings also tend to be safety settings (because privacy help to protect your safety). The above scenario could have gone a LOT worse and underscores the need to keep those privacy settings fresh and configured the way you need them to be.