Top of the DKos rec list: Man with a gun? Call 911.
Short and sweet.
Silence is complicity, so if you have a problem with guns being displayed in public, call the police when you see it happening.
I await the many comments explaining why this is a simple-minded and sophomoric action to take that Very Serious People should ignore.
Fits nicely onto a bumpersticker, too.
1) It’s going to get people killed 2) calling 9-11 on legal gun owners who aren’t breaking the law is illegal.