TOR is an anonymous browsing program. When a TOR user posts on the boards their post gets an ID of 000000 because of the untraceable nature of their web browser.
When someone responds to a post on 8kun, it gets linked. If their post is in the same thread as the TOR poster the TOR post keeps the 0’s. But if they respond to a TOR post from an older thread, it gets a new ID instead of the 0’s.