But Cowie said that cutting off a country's Web access to deal with a cyber threat is like cutting off the entire lower half of a person's body after a snake bite to the ankle.
"It's such a blunt attack on yourself," he said. "I'm already stunned that Egypt would dare do this to themselves. ...Imagine how much business with Egypt is done on the Internet every day. If there's no Internet when everything opens up after the weekend, what happens to the trade? What happens to their credit rating on their sovereign debt?"
In the U.S., not only could the consequences of that scenario be devastating, the coordination to get a "kill switch" program off the ground would be a huge undertaking.
"Imagine that situation in the U.S., where, certainly, you'd get a lot more suspicion and push back from providers," he said. "I just don't see a kill switch going anywhere."
Craig Labovitz, chief scientist for network security and monitoring firm Arbor Networks, said his company also observed a sharp drop off in Internet traffic in Egypt Thursday.
Today there's just "a small trickle of traffic that appears to be going in and out of the country," he said.
Noor appears to to have some routes open, and it looks like there are a few open routes through other Internet providers, he said.
While some Egyptians have been passing information about Web proxies, which are services that let users bypass blocks on specific websites, Labovitz said those proxies can't help when most Internet providers are shut down.
Still, Egyptians could possibly connect to the Web if they have satellite phones or dishes. Those on the borders could also potentially get cell coverage.
"Radio waves don't obey borders," he said.