Google was sued this week over its selling of keyword advertising. The American Blind and Wallpaper Factory accuses it of trade mark infringement. Google recently filed its own suit asking the court to declare that its policy did not infringe on brand owners' rights.

The controversy concerns Google's AdWords service, which allows advertisers to sponsor particular search terms so that, for a fee, whenever that term is searched the advertiser's link will appear next to the search results.

The company does respect unarguable trade marks. Reebok is unlikely to succeed in sponsoring the word 'Nike', for example; but 'sportswear', being a generic word, would likely be available to anyone.

But the American Blind & Wallpaper Factory complained to Google about its sale of certain words that it said were protected by its trade marks.

Google agreed to stop selling terms that were clearly related to the trade marks – such as 'American Blind Factory'. But, the search engine company refused to block what it considers to be descriptive or generic phrases, such as 'American blind'.

On Tuesday, American Blind filed suit against Google, America Online and AOL subsidiaries Netscape Communications and CompuServe Interactive Services, Ask Jeeves and EarthLink.

According to CNET News.com, Steve Katzman, CEO of American Blind, said in a statement:

"We spend millions of dollars annually to build brand awareness and cannot stand idle while Google allows our competitors to ride our coattails."

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