The posts in the trash don't count for your post count, so if a thread gets moved to the trash, you lose the count from those posts. Say you had 10 posts in a thread, it gets trashed, you lose those 10 posts from your post count.
But yes, I have seen some vindictive modding, but you have to remember, they're still human.
Ubique Quo Fas et Gloria Ducunt
Alternatively, I could just light you on fire. - Me