Yes, an admin has to delete accounts. Or we could just ban them (with the understanding that we're not banning them with any kind of disciplinary reason.)
Even if you ban them, the account still exists, can be searched, all original info and stats are there including posts/threads etc... All it does is make it so that the person can't log in or post.
Tom is an administrator. I just searched the forums for the oldest post using the word "forum". Turns out I could have just looked for the oldest user, user number 1. He hasn't been here in years. If there are any others, I wouldn't know how to find them.
We don't delete accounts, but if there's any personal identifiable information you'd like removed, just provide direct links to the content and I'll edit it out for you.