Remind them of what they don't like about the government and that they're advocating so hard to give a monopoly on the use of force to that same government... and the corporations that controls it. It's making them stop and think more than anything else I've tried.
" I saw this yesterday and I rolled my eyes and blew it off as another right wing anti-occupy jab that needed no further consideration. Then I gave it further consideration. This is exactly what so many on the left are asking for. It may not be what they want but it's what they're asking for. So many times since this most recent shooting I've heard the cries that only police and military should have guns or should have "those types of guns". This is the police force that you want to hand more power to. This is what you're asking for, a police state that you will be completely powerless to resist no matter how far they go because you've happily and willingly disarmed yourselves and everyone else. You're trying your best to make sure that the agents of the rich and powerful get to have the big guns and we don't. You scream and cry for tougher gun restrictions for everyone but the elite that can get whatever they like.
You really don't want to do anything. You just want somebody else to do something. It's just like the right keeps saying about you."