Yesterday on Instagram, Lena Dunham reposted and endorsed a plea from Girls co-producer Tami Sagher for New Yorkers to tear apart subway posters for the upcoming film Jason Bourne because the posters show Matt Damon holding a handgun. Let’s meditate briefly on why this is useless.

For one thing, obviously, defacing posters in New York City subway stations will have a net zero effect on the world. If tearing down subway posters meant anything, Girls itself would not be on its fifth season.

But more importantly, “guns in movies are bad” is the exact sort of conversation people like the NRA would like for America to have, because it briefly distracts us from the real issue, which is the intractability of gun laws in America. This phenomenon dates back at least as far as Columbine, in which the world was tricked into thinking that one of the worst school shootings in history was caused not by guns, but by Marilyn Manson and goth clothing. This is also a problem that crosses the aisle—hopefully when Hillary Clinton is president, she will attack actual gun legislation and not video games.

I don’t mean to pick on Lena Dunham, who, like me, would like to see guns eradicated from America, and who has been using her Instagram for good in this time of intense social strife. But let’s just remember that Matt Damon and Universal Pictures are not the real enemy here.