As reported, a terrorist attacked a group of citizens standing at a bus stop in Israel, using his car and then a large knife, but was then stopped by an armed citizen. The incident was caught on video.
The video, which is rather graphic, is shown below:
Armed citizens can and do stop terrorist attacks. Indeed, I have discussed multiple previous instances where terrorists have been shot by armed citizens, saving lives. The police cannot be everywhere, and so the the only realistic way to stop a terrorist before they can cause great harm is to have armed citizens ready to act when a terrorist strikes.