Just my opinion, but I think people over estimate the "behind the scenes" security. It seems like some watch too many movies. But I feel like believing that helps people relax and feel more safe. So that is good. I agree, checking all strollers,
ECV's (driving over a mirror or clear platform, checking the battery, etc) seems prudent. I know I will be more alert to my surroundings when we visit like many here discuss, and I feel that if everyone does this and is not afraid to report anything shady, the world will be a safer place. Just so sad for those families affected this week...