That is an URL that I had never seen before and it totally baffled me. I tried entering in my user ID instead of theirs, TERKSON@active.directory.com, and got the generic "That page could not be accessed." error.
So I asked the user about it and they said it probably had something to do with it being a saved custom view. Huh. So I went to the viz and sure enough, it was a saved view:
We use Active Directory for authentication so the custom view was saved under the AD account ID followed by the custom name. Mystery solved and now you know how to read these different view URLs!