UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? How do we remove old users with non-validated emails?

There are several other tables as well. ubbt_USER_PROFILE, ubbt_PRIVATE_MESSAGE_USERS,ubbt_PRIVATE_MESSAGE_TOPICS,ubbt_PRIVATE_MESSAGE_POSTS

What you might consider is using the member management tool in the control panel. With that you could specify a search for users that haven't logged in since a certain date and have 0 posts, that might catch a lot of those users you're looking for.

From there you can specify to delete those users and it will clean up the appropriate tables.