Google's so-called 'Bing sting' is clearly a very effective attack from a propaganda perspective, but is poor practice from a company that claims to do no evil. Generating and sending clickstream data deliberately so that you can then subsequently claim that your competitor 'copied' that data from you is neither fair nor reasonable, and suggests to me a degree of desperation in the face of real competition.   Monopolies are undesirable, whether they are Microsoft monopolies or Google monopolies.    Personally, I'm glad Microsoft has technology in place to observe user behaviour (with permission, of course) and improve their search results using such data. I can only assume Google doesn't implement similar capabilities. Sounds to me as if, at least in this respect, Microsoft may offer the better technology.