It seems that being "off topic" and "personal attack" are good reasons to delete a post. But they are not applied evenly to all posters.

I suggest a safe way to use discretion when moderating, and not come accross like a hypocrit, is to simply say that you are removing a post due to your discretion, and quit using the PC friendly "off topic" etc, cause once you post that as a reason for one removal, it technically must apply to all. So sad :(