You might have heard about the lawsuit by a dating site against Yahoo that supposedly bought Google's AdWords that allegedly infringed on the dating site's trademarks. Intrigued by the irony of the situation, I used this handy tool called Googspy to see what other AdWords Yahoo's been betting on. I counted 10,020 of them. Microsoft, which also has its own search engine and an ad application, is paying for just over a 1,000 of AdWords. I don't know how accurate Googspy is, but the few random searches indeed showed the respective ads by Google's two competitors. Quite a few of these words are trademarks, so it will be fun to watch how the suit turns out.
In 2004, Geico filed a similar suit against Google itself and lost. "The judge said that as a matter of law it is not trademark infringement to use trademarks as keywords to trigger advertising."