Personally I'm fed up with single entities such as Microsoft using TLDs for every damned thing, it makes it very hard to identify what is and isn't legitimate traffic. It also makes it borderline impossible to configure "whitelisting" firewalls or proxy servers.

I got to wonder what fraction of this is incompetence ("we can't use our own domain because of bureaucracy") and what fraction is deliberate ("everyone has blocked microsoft.com so we used something else")...