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Those guys at M$ are a bit nutty, and I have seen IP addresses resolve to M$ corporate surfing as a regular browser, but I'm not sure if I've ever seen a bot do it personally.
I have heard people have access to their IPs to use at times, but I'm not really sure I've experienced them not following the rules personally. Maybe there's some other reason they're visting the page or being redirected and it just seems like they're totally spoofing their UA?
Uh, you know they're spidering as bingbot now, which would correctly be sent to that page when coming from one of those IP ranges, right? ;) I made this text small, because most people don't read this stuff, especially if I put enough of it to make it look like it's work for them to figure out what I'm trying to say. Hope you enjoy your stay here at WebmasterWorld. Personally, I really enjoy the knowledge and discussions.