I am not sure what your "local bulletin board" is....like at a church or something? Yeah, don't think this guy is doing that.The local bulletin board. It's not hard. But you keep on trying to demonize those you see a different political bent for the problems and the problems will continue.
Moreover, I have never seen guns advertised there. I suppose you could do like facebook marketplace...but never seen guns for sale there, moreover it would require some sort of travel...and Facebook could shut that down without any federal or state law being passed