I don't think I've had any posts deleted, but it's still really discouraging to find out about and, yes, kind of makes me angry when I realize that's what's been done.
Don't get me wrong, I could see it being useful in certain extreme cases, but to do it so nonchalantly and not addressing the issue broughtup is really inconsiderate.
Also, some previous guidance seems to have been changed:
"moderate yourselves as much as possible": don't address problems and if you do, mods will delete your posts and ignore the problems (including rudeness - repeated and otherwise - from other posters)
"you can't control the direction of the thread": If a thread goes off topic (no matter how useful, polite or appropriate the discussion), mods will lock the thread or, again, make posts "disappear"
"You can politely call posters out on their bad behavior": Now, it seems it has become Support Group Hell instead of Etiquette Hell. There have been several instances where posters' behavior was called into question and the only ones to be mod-smacked were those people who dared say the OP was rude or (again) their posts were made to disappear.
The direction, purpose, and policy of the board seems to be going in a different direction than in the past and I would like some clarification.
ETA: Also, seems we can add, "Don't discuss issues with threads/posts being disappeared/edited or we'll make the whole thread disappear."