wilderness - 4:05 am on Mar 19, 2013 (gmt 0)
FWIW, it doesn't matter what UA they represent themselves as (especially when Bing and NOT coming from a legitimate MS IP offering valid DNS).
In the this instance, the IP goes all the up to the backbone:
Rackspace Hosting RACKS-8-NET-4 184.108.40.206 - 220.127.116.11
There are multiple mentions of this server farm in the archives and there should even be a comprehensive listing of all their IPs.