but to do what is not entirely clear. As I picked up from the Trademark Blog, it appears that a lawyer representing Avis has told a legal blogger that he has no "right to use Avis' trademark as [he did] in this particular piece." The piece happens to be a report on a decision invalidating a federal law granting car rental companies immunity from negligence liability in certain circumstances, with which Avis is no doubt concerned. The blogger illustrated the report with the Hertz and Avis logos.
The blogger has asked for comment, and as he called me out by name, I will say something (though he is of course aware that I am not his lawyer!): even to analyze the ways in which an infringement or dilution claim must necessarily fail in these circustances is to give this -- charitably -- overzealous claim more respect than it deserves. Eric Goldman nicely points out in comments that Avis's move is dumb both legally and from a marketing standpoint; I'm in full agreement.