Who said anything about civil war?
The US has many splinter loon groups who blow up buildings and like to attack infrastructure (see: US news). This has happened over the past decades with no civil war.
Data centres are soft targets - softer than banks. Do you remember when armed bank robberies were all the rage in the 1970s and 1980s? Not a time of civil war, just a time when a couple of people took control of buildings while heavily armed. Such a small group with fragmentation grenades can easily render a data centre unfit for use for several months with relative ease and fast ingress and egress.