IGun

Guns should have electronic chip, which would allow their use only when majority of people around approve it. Think IGun. Now if a terrorist kills a guard and gets his gun then he wont be able to use it on hostages, unless they themselves allow his gun-use by pressing "confirm" on their smartphone.

That way lone gunman and a-few-terrorists scenarios will get eliminated, but when a large group of people comes out to protest, totalitarian government wont be able to stop them from exercising their democratic rights.

Same way people would be able to hire a sheriff and give him right to police some locality, without fearing he will use the gun against to subvert democratic procedures.

What do you think?

>>19
These six terrorists can at max kill only six people. No way they will be able to take whole building hostage. Therefore not very efficient. Also, building owner would likely limit gun use only to building guards.