> The most concerning part, users say, is that Facebook does not notify them when their posts disappear from public view.<p>IMO a fundamental lack of transparency is sometimes the biggest frustration across a great many big services. While it's sometimes explained as "we can't give more details or bad people would figure out how to bypass it", more often than not it feels more like "we don't know why we the magic box decided this but the magic box is always right because caring about it costs money."