If you don't defend your trademark, you can lose it.
"Jack Daniel’s Cease-and-Desist Letter Goes Viral for Being Exceedingly Polite"
https://www.abajournal.com/news/article/jack_daniels_cease-a...
Couldn't the trademark holder in these situations simply license the mark to the other side, for some nominal fee?
Same for the Jack Daniels case. The book cover is probably fair use through parody, but even so, Daniels could simply license it to the author and request that the next printing have "the cover design is a trademark of Jack Daniels Properties, Inc.".
But the upside about this lawsuit is it will tell us very clearly if you're correct or not.
Note: I don’t dislike OK Go at all, don’t get me wrong, I think they make some of the most creative music videos I have ever seen.
However, even your own retelling is misleading in the other direction, leaving the impression that OK Go is keeping this hanging over the poor company's head: OK Go apparently threatened to sue Post ("Post said OK Go had been quietly threatening to sue for months, claiming that the company had infringed the trademark rights to the band’s name by launching the new on-the-go packages earlier this month.), but didn't actually do so.
But if you look later in the article, you see that this whole thing came to a head only 1 week after their last failed negotiation attempt: But the food company says OK Go rejected that offer last week and made no counter-proposal, leaving Post with no choice but to file a lawsuit. Citing a “clear threat of potential litigation"
So there's no real fire here in either direction; in fact there's no actual story at all. This is just standard procedure that you'd expect to see in any trade mark dispute, done in a regular orderly fashion (hyperbolic PR sound bites notwithstanding).
Post was planning to release some on-the-go versions of their cereals under a brand called "OK GO!" This seems like a pretty reasonable thing to do. I certainly don't feel like they chose that name for the purpose of somehow confusing consumers into thinking their cereal was related to the band (nor can I imagine anyone accidentally making that mistake).
OK Go apparently threatened to sue Post ("Post said OK Go had been quietly threatening to sue for months, claiming that the company had infringed the trademark rights to the band’s name by launching the new on-the-go packages earlier this month.), but didn't actually do so. Post filed a lawsuit that didn't request any kind of damages, just preemptively asked the court to rule on whether their new cereal brand infringed on the band's trademark ("Post is seeking what’s known as a “declaratory judgment,” meaning a ruling by a judge that says the company did nothing wrong.).
That seems like a perfectly reasonable thing to do - there's a dispute over whether Post can use the name, and Post is just trying to get clarity on whether it's okay or not from the court.