Re:?

Registered users: Bing [Bot], Google [Bot], Majestic-12 [Bot], MSN [Bot]

What is the purpose of the above named registered users?

Search engine bots that crawl the site for Bing, Google, Majestic-12, and MSN, respectively. Giving them user accounts lets them see a stripped down version of the site to reduce overhead, and makes it easier to give them access to user-only forums or to exclude them from public forums that shouldn’t be indexed.

Thank you, Carleas.