Are you basing your argument on some knowledge of trademark law, or are you just pulling this out of your rear end? I don’t see how the argument that O’Reilly *created* the term “Web 2.0” as the title of a conference, and therefore they have a right to prevent other people from creating competing conferences entitled “Web 2.0” is simplistic. A few searches of the O’Reilly site seems to confirm that they don’t make any other “Web 2.0” branded products, so I don’t see why you would expect them to try to protect their trademark against non-competing use of the trademark in blogs, book titles, etc.