Wouldn't it just be a law requiring ISP's to kill peering upon the government's request? Am I missing something here? If it isn't feasible, I would think that's because it isn't legal, not because of a technical hurdle.
Instead of a Kill Switch, I think it would be possible to make a Flood Switch. When enough shit would hit the fan, to make the president issue the Kill order, all bets would be off.<p>Let's say Americans are using Twitter or a foreign website to organize riots in a civil war, I don't think once the order is given and such a bill is in place, that the government has to ask nicely and force compliance. It will put all government computers and some very big tubes into DDOS'ing whoever is publishing something they don't want published at that very moment.
From a brute-force PoV, I imagine you can have armed FBI agents in the offices of major ISPs in an hour or so. If they block their customers and they also block their resellers, then really you can handle most of the Internet with probably a dozen 2-man teams. It's not really that critical if it's deemed too hard to block two guys on the same local ISP from chatting.<p>Not to mention that even rudimentary steps - knocking out DNS or even just Google, Yahoo, and Bing - would put 95% of Americans effectively offline.<p>Metcalfe's Law works both ways - if you cut off even 3/4 of the internet, it's now only a square-root of a square-root as valuable as it used to be.
You could certainly bust the internet into a lot of small unconnected subnets, simply by telling all the backbone providers to disconnect peering. I would expect that .mil and continuity of government circuits would be tagged as exempt, and would continue to work.<p>I dunno what happens if your provider happens to be someone like Hughes or DirectPC. That's one heck of a large subnet.
If the kill switch is built into routers, expect that to be used by hackers. You'll have to use open source router code like dd-wrt to avoid it.<p>This is a bad idea and is trying to change how the Internet works. The Internet was designed to stay on even if there was a nuke attack. ISPs have been handeling DOS attacks for years successfully without a kill switch.
And note, if a 'kill switch' is ever required, the agency that will enforce its adoption by ISPs? Just as with wiretap requirements and broadcast language/content censorship, the FCC.<p>Remember that before cheering on the FCC to have authority over which ISPs are sufficiently 'neutral'. (And don't be surprised when 'neutral' gets redefined over time into 'compliant with the FCC's political biases'.)