I’ve recently noticed in my logs lots of visits to my posts from a Microsoft IP block (the last one was 22.214.171.124), supposedly with a referrer of http://search.live.com/results.aspx?q=[random keyword]&form=QBHP .
My posts never appear on the search results page, in fact some keywords are completely irrelevant.
I found this post on Blogboing (and this older one), and this fuller explanation (including instructions on how to block it), which partially explains them, but the Microsoft response is clearly rubbish. As far as I’m concerned, this is just referrer spam, and another reason not to use Live Search!
I don’t think I’ll block them for now, but may do if it continues.