Cybersecurity Act would give president power to 'shut down' Internet
Er, the Internet is a whole lot bigger than the little bit of the super information highway ring road based in North America. Closing down that small part of the information highway only really serves just to keep the drivers using that little bit of the super information highway ill informed about what would be going on in the rest of the highway. But then again maybe thats the idea behind that proposed piece of legislation.
They already have major traffic light operations on the super information superhighway on the borders with China only allowing compliant information to pass through those traffic lights.
is it even possible to shut down the internet?
From the perspective of the average user using the internet then the answer is Yes. A US Government official would just tell the compliant ISPs (under threat of being prosecuted under the new law) to drop their customers connections and then refuse those reconnections at the ISPs Remote Access Servers.