Backrooms is a cultural artefact that was created in the commons. The idea of any degree of ownership is nonsensical and it's ludicrous they tried.
I mean, this but all IP.
The Trollface guy did apparently get a copyright upheld and tbh that was one of the things that put me off copyright.
I once heard Hollywood described as a network of law firms that happens to make movies. It's the most litigious industry on Earth, or one of them. They don't just sue you and I. They sue each other constantly, battling over royalties and residuals and rights and IP theft (which does happen in Hollywood of course).
I love good film as art but the industry seems certifiably insane in lots of ways: litigious, nepotistic, backbiting, full of sex abuse and other nastiness. I have sympathy and respect for anyone (actors, actresses, writers, etc.) who love the art enough to deal with that crap.