It may be that what Fortres Grand was really worried about is that Warner Bros.’ use of the term “clean slate” would taint Fortres Grand’s “Clean Slate” mark, and make it seem less appealing or less distinctive (though if it wanted distinctiveness, it should have used a less common term than “clean slate”).
But this sort of “trademark dilution” claim requires that the mark be a “famous mark,” something that’s likely not true of Fortres Grand’s mark. And this sort of trademark dilution claim is likely unavailable for uses of a trademark within a song, a movie and the like (see Mattel v. MCA Records (9th Cir. 2002), the “Barbie Girl” case). Even trademark confusion claims are often preempted either by statutory or First Amendment considerations when the trademark is used within such a work; but trademark dilution claims are even more clearly barred in such situations. Probably for these reasons, Fortres Grand litigated only a confusion claim, not a dilution claim, and the Seventh Circuit concluded that “it would not be appropriate to use a contorted and broadened combination of the ‘reverse confusion’ and ‘related products’ doctrines to extend dilution protection to non-famous marks which are explicitly excluded from such protection by statute.”
The Seventh Circuit opinion also includes — likely facetiously — a “spoiler alert,” but this is actually the second court opinion to include a “spoiler alert” related to a movie. (The first was just a few months ago, State v. Molner (Wisc. Ct. App. June 3, 2014), related to “Primal Fear.”) It may be the first court opinion, though, to discuss Batman’s alternate transterrestrial contacts: “Unlike other depictions of Batman, such as his appearance in the Justice League comics, there are no alien races from other planets, so wiping all traces of oneself from earth’s databases is sufficient.”
The UCLA First Amendment Amicus Brief Clinic, which I run, filed a friend-of-the-court brief on behalf of the Electronic Frontier Foundation, supporting Warner Bros.; you can see it here. I should also acknowledge that I am indeed badly mixing sub-mythoses here, between the case, the headline, and the image on the blog front page.