I used to be an ISP so I know about shutting the internet down. It's doable, there are 4-6 main "choke points" in the U.S.' network that once shut down, literally disables the 'net. Hell, the telco's get one government order to shut down and you can kiss the whole 'net goodbye.
Simply revoking amateur operator licenses isn't going to have the same net effect as shutting down the internet, specially when one considers there are approximately 1,000,000 ham radio operators in the United States alone.
It doesn't take a whole lot of power or big antenna's to send signals around the world either, so it's not like the government can drive down the street and look for towers with lots of metal in the air. Sure, some like me have a big tower with lots of antenna's up in the air, but that's not the majority. Most of the licensed ham's I know use more stealthy means of transmission such as wires in tree's, flagpole antennas (they look like real flagpoles) and antenna's in attic's or under gutters along the roof lines they're a lot harder to find.
It'll be a hell of alot harder to shut down the ham's than it will be to shut down the internet, that I can guarantee you.
By the way, if you have a shortwave radio, tune into 7.240 LSB some evening after oh, say 9pm. All it takes is one guy keying up yelling "Obama Sucks!" to bring out the true feelings of the Amateur radio community on a very large scale, towards the current occupant of the White House. It's alot worse on 80 Meters late at night above 3.920. You can't find an Obama supporter anywhere on 80 meters. It's like the wild west.
I know it’ll be harder but the government would be looking for you. I remember back in the sixties when C.B radios were the craze. Some went all out with home bases with tall antenae and would talk “skip” all over the world. At that time there were fed agents out looking for people to fine.
There’s no doubt that ham operators would be better off. And for those who don’t know what it’s like to be in the dark, they’re in for a surprise. During Hurricane Ike it was strange to not know what was going on. I was on the cell phone with my sister out of state and she was giving m updates. I can only imagine what it was like for those who had no cell service. And this only went on for a day or so before local media was back up and broadcasting. One radio station never went off the air. If the government controlled all media and only told what it wanted the people to know, they’d have us under their thumb.