By Fiona Leishman Mobile phone users across the US have woken up to disruption this morning as several major carriers have gone down. AT&T, Verizon, T-Mobile and other network providers have all been impacted in a network outage that has impacted people from California to South Carolina. Providers did not immediately share a reason behind the network outages, leading many to worry that it could have been part of a larger cyberattack on the US. According to Downdetector, AT&T, Cricket Wireless, Verizon, AT&T’s FirstNet, T-Mobile, and smaller carriers such as Boost Mobile and Straight Talk all w…