We didn't delete anyone's comments. http://slashdot.org/comments.pl?sid=3455889&cid=42890287
We don't delete comments (there are plenty of negative ones here to read as proof). I'm assuming the post you are referring to is http://slashdot.org/comments.pl?sid=3455889&cid=42879165. Although I'm not sure why you can't see it since it at a "2" right now. Are you only looking at comments rated 3+.
When you press the "Flag this comment as inappropriate" button that comment ends up on a big list that the editors go through each day. Usually it's filled with user comments that other users don't like, and sometimes theories that we're deleting comments. We try to respond to the conspiracy theories and ignore the complaints about not liking posts for one reason or another. That's what the moderation system is for. Every so often however someone uses the button for it's intended purpose, which is to quickly downmod the worst trolls and to identify spammer accounts so we can ban them. The button is to make sure the gnaa crowd stays at -1 and to keep the spammers out of discussions. Feel free to continue to be inappropriate.
The faster I go, the behinder I get. -- Lewis Carroll