Just imagine the runs on banks for cash because debit cards no longer work.
Nearly every business, except maybe some mom&pop types, relies on the Internet -- for credit card authorization, for sales tax, for JIT processing, for numerous other things.
A shutdown of even a day would do so much economic damage that it would take weeks to recover. Look at how interruptive a 2-hour outtage is for many businesses.
Look at how many individuals and businesses rely on online bill pay.
If the government (Homeland Security or a particular administration) think they can just flip a switch and shut it down, they have no concept of what is or how it is used.
Congress needs to step in a explicitly forbid it.
Congress, especially the Senate, with one of the Maine ladies and Lieberman (IIRC) are the instigators of this madness.
The new digital police radio systems rely on an internet backbone;if the internet goes down the vaunted interoperability is lost and they can talk only through the local tower.
But the militarp spread spectrum comm gear would still work .
An internet shutdown would be a sign of a tyrant taking control.