Certain words may have been censored by the administrators or moderators. If your posts contain any censored words, they will be blanked-out like this: *****.
The same words are censored for all users, and censoring is done by a computer simply searching and replacing words. It is in no way 'intelligent'.
There are some instances when administrators and moderators may remove whole posts - especially when it is deemed unnecessarily provocative and indicative of 'flaming'. Forum admins and mods also remove blatant spamming and forceful advertising from troll members.