I'm going to change this soon. What i did was have all deleted threads go into a 'queue', so they are deleted from the board but still accessible via the admin interface. This way I can reference rule breakage should I need evidence to support a ban. I will change it so that you will have an option to 1) permanently delete or 2) move to mod queue. That way you can send it to the queue if it's something that should be saved for evidence, or just wipe it totally if not. Right now the mod queue is filling up too fast with junk (thanks for doing your jobs, y'all
