[01/02/09] I have deleted a number of old accounts with zero posts that had no been online in more than 4 months. These users are free to register again, however it is advisable to those who have not posted to maintain activity with their account to ensure it does not get deleted.
[05/11/09] Remember folks, inactive accounts with no profile fields filled out and no posts are likely to be deleted. Going to be doing a small pruning here in the next few days, deleting the unconfirmed accounts as well as some of the older dataless ones.
[01/05/13] I deleted a few accounts with posts that had not been on the site in over 3 years. Additionally I deleted most accounts with 0 posts that had not been on the site in over 6 months. If you are a lurker and have 0 posts, it's strongly suggested to make at least one post somewhere, as I'm less likely to prune an account if it appears to be active.
[06/12/14] I will be doing another user prune in a month or so. I will make sure to have completed an art and video update before doing a prune, however, to ensure that long time visitors/lurkers that still legitimately intend to be a member of the site have a chance to log into their account again. As a note, I almost never delete accounts belonging to people who have contributed in the past.