Remember back in the earlier days of the internet, when there were so many fan sites dedicated to various TV shows like the X-Files, Buffy, and so on? The studios, especially Fox with the X-Files, were notorious for demanding these sites be shut down. No matter that they were providing free publicity for their shows, no matter they were encouraging new viewers, all they could see were "trademark infringments" and "copyright issues". Fox, especially, were particularly heavy handed in their demands, bringing down the threat of unlimited litigation which they (Fox) could afford, but no one else could. It's actions like this that make me less concerned with their "shareholder obligations", and more concerned about their lack of civility and, frankly, hostility towards the consumers of their products - Us.
Same with Warner in this instance. How could a theme night in a little suburban resturaunt hurt a huge conglomerate like Warners? What harm are these people doing? If anything they are, like the fan sites on the internet, providing the studio with publicity, and good publicity at that. This is providing as much publicity, but is it good?
The Fun Police rule.
BTW, if my comments above gave offence to Fox or Warners in any way, then Good... my job here is done.