Question: I deleted an old answer that had a -3 score, and didn't get a peer pressure badge.

If it's not intended to be awarded more than once, it loses its reason to be, that is encouraging people to delete (what the community considers) bad posts.

Should it be awarded more than once or not? If it is, could it become like the [troll cap](http://37signals.com/svn/archives2/introducing_the_troll_cap.php)?

Answer: 
It's awarded just once. I'm tempted to say it should be awarded for each -3 post you delete, but I'm not so sure that's something we want to celebrate more often.
This would encourage some users to try and rack up the most Peer Pressure badges on the site. No thanks.