Yes, by refusing to watch, and perhaps make the kind of movies that glorify and apparently cause violent behavior.
Why don't the liberals pick on the 1st amendment the same way they pick on the 2nd amendment? Why aren't they calling for Hollywood to stop making movies that set off lunatics? Wouldn't that be "reasonable"?
Ownership of firearms by citizens provides a vital benefit to all of society. What benefit does the Batman movie series provide?
The batman series provides a good benefit actually. It shows perseverance against overwhelming odds. It shows that just one man with no super powers of any kind can be a hero. It demonstrates that heroism is about sacrifice and responsibility and that sometimes even those with pure motivations can be misunderstood. It also shows that no matter what we do, how much we sacrifice, how hard we try, we can still fail but that true heroism is about getting back up and trying again after we have failed.
But if you aren't into it that's cool with me. Just don't play liberal games with the 1st amendment.