I’m not a trademark lawyer, but I think Google™ pretty much has to behave this way (via Dave Winer). I believe that there is a gotcha in US trademark law by which you can lose your trademark by unintentional abandonment. One of those ways seems to be if the term becomes generic.

5pm It’s not really being a bully as much as it is them trying to protect their identity. Similarly, property owners shouldn’t let random people cut across their property as a shortcut. I believe that under the right [wrong?] circumstances the shortcut can become a permanent public easement.

6pm Hmmm, Cory Doctorow believes that the standard for abandonment is much higher:

Allowing the generic use of “to google” by critical/academic sites like WordSpy does not constitute an abandonment of trademark (in fact, trademark abandonment involves a very high standard that is far in excess of allowing people to casually use your mark).

I’m just a bit sceptical about the parenthesized comment. Suppose google became a commonly used verb that meant “to search online” (not “to use Google™ search”). Then suppose that a website re-labeled all their search buttons to read “google”. What recourse would Google™ have?