Terrorism, Statistics And Fear

" - - - although the probability of an attack may be low, it may get higher. If you think of car accidents or the background rate of murder in the U.S. as a chronic disease, you can think of terrorism as the Ebola virus. Yes, the chances such a virus will infect any of us in the U.S. are small, but if it gets established, things could get very bad. When someone with Ebola manages to get to the U.S., we don’t dismiss it by saying, “Look, a lot more people die of cancer!” The alarms go off and stringent health measures are taken."

 https://whyevolutionistrue.wordpress.com/2016/01/03/lawrence-krauss-on-terrorism-and-statistics/