An estimated 240 million calls are made to 911 in the US each year; each US resident makes, on average, more than one 911 call per year. 911 centers had been directly or indirectly attacked in almost a quarter of those cases, most of which involved distributed denial-of-service (DDoS) attacks. Every industry sector now relies on Internet connectivity and 24/7 access to online services to successfully conduct sales, stay productive, and communicate with customers. DDoS techniques have evolved to use Internet of Things devices, botnets, self-learning algorithms, and multivector techniques to amplify attacks.”]