[aotagain]

Google have a neverending flood of trademark complaints and this might put the ball more into individual companies courts to deal with each other directly by spending money on lawyers, rather than involving Google (who don't get paid directly for their policing).

Where you have some companies bidding on each others keywords, this becomes complicated as many companies are paying for offline brand exposure, the benefits of which can then be 'piggybacked' by other companies. I'm sure Google would prefer not to be involved in the middle of disputes if possible, particularly those involving issues of who 'owns' a keyword; what was the intent of the person who put the keyword into the search; is a keyword used as a generic term eg. Hoover; is a keyword part of a domain which would otherwise be considered just another part of the language eg. should a company called 'Flight Deals' have any right to stop anyone bidding on 'flight deals' as a phrase match etc. etc. (just thinking of the nonsense surrounding the Easy empire !).

Passing off by using a actual trademark in an advert is an entirely different matter and is a clearer legal issue and more easily policed imo.

In the 'real' world, there are long-established precedents when it comes to using some other company's logo or name in an advert, especially if monetary gain is likely.