The sign/card amounts to basically allowing the evil of the gun to proliferate. Remember the gun is not good, it was not inspired by good forces, it was not designed for good purposes.
Is pretty funny though as it displays the typical backwards thinking of the gun crowd that wants to have us regress back to Wild West anarchy. Hence the pop culture allusions to Wild West saloon shootouts.
We'll just keep Mad Dog Tannen on the silver screen and out of our reality until the day all the diabolical guns can be turned into rust and dust.
https://www.youtube.com/watch?v=wEByIZn5qeU
[video=youtube;wEByIZn5qeU]https://www.youtube.com/watch?v=wEByIZn5qeU[/video]