Control of the internet and social media is a huge deal these days. Almost everyone is connected to it. Information can move world wide in seconds. The government can learn what is going on in a specific event in a moment as can terrorists. In many cases it is better than a satellite feed. Someone is streaming video from their phone of a riot or maybe a terrorist attack. When it hits the net everybody knows in short order. If you are the terrorists your suprise is blown quickly as the news spreads. If you take out internet and social media it will buy time to accomplish your goal before too many are alerted and try to stop you. It works the other way too though, if the government starts taking over a city or declares martial law the news will spread quick and they will meet much resistance. Controlling the flow and content of info is power no matter what side you are on.