Perhaps I wasn't very clear in my original post as to just what I'm asking.
If I log in to Bing Webmaster tools over an unencrypted connection, then my details may be intercepted, giving a third party access to my account. OK, so the details of any web sites I've added may not be that sensitive, but they can also access my own details - and Windows Live ID asks for information such as gender, year of birth, location, that other services don't require. In addition, they helpfully tell me that I can use the same ID to access Hotmail, MSN Messenger, X-Box Live, etc. I don't use any of these services, but if I did, I can use my log-in over an unencrypted connection to Webmaster Tools, and some bad guy gets free access to all my accounts, my e-mail, my messages, my personal details etc. Surely that's a cracker's dream?
But why would a huge company like Microsoft do something so stupid? Surely I must be missing something here, or have misunderstood how these things work? Bottom line: who's losing their marbles - me or Microsoft?