Bruce Schneier may be exaggerating here, but he has a point about where a lot of companies and government agencies would like to take us. However, I think defeating this fear may be a lot easier than he realizes.

OnStar will soon include the ability for the police to shut off your engine remotely. Buses are getting the same capability, in case terrorists want to re-enact the movie Speed. The Pentagon wants a kill switch installed on airplanes, and is worried about potential enemies installing kill switches on their own equipment.

Microsoft is doing some of the most creative thinking along these lines, with something it's calling "Digital Manners Policies." According to its patent application, DMP-enabled devices would accept broadcast "orders" limiting capabilities. Cellphones could be remotely set to vibrate mode in restaurants and concert halls, and be turned off on airplanes and in hospitals. Cameras could be prohibited from taking pictures in locker rooms and museums, and recording equipment could be disabled in theaters. Professors finally could prevent students from texting one another during class.

The possibilities are endless, and very dangerous. Making this work involves building a nearly flawless hierarchical system of authority. That's a difficult security problem even in its simplest form. Distributing that system among a variety of different devices -- computers, phones, PDAs, cameras, recorders -- with different firmware and manufacturers, is even more difficult. Not to mention delegating different levels of authority to various agencies, enterprises, industries and individuals, and then enforcing the necessary safeguards.

Obviously you can't explain that the easiest way to dissuade companies and agencies from this path is to simultaneously disseminate the information used to lock down the private property, and then encourage people to act on it. I think it would be not only a great act of civil disobedience, but an interesting experiment for an enterprising Computer Science or engineering student to make a transmitter that can broadcast the shutdown code to every car on a busy highway during rush hour traffic. That way, no one is likely to be hurt (except by road rage, maybe), but it is likely to create one heck of a powerful public backlash should this technology every actually be put into mainstream use by government mandate.

I'm not convinced that the government will really get very far with this sort of thing just because of the fact that it will be so easy to abuse. Like the backdoors that government wanted in all encryption products in the 1990s, these technologies that are supposed to "help law enforcement" will invariably fall into criminal hands, making them useless for the public and law enforcement. As we know from history, the government simply had to stand down over encryption because the measure of control that it gained over private information was outweighed by the sheer volume of crime that was a likely outcome of forcing the public to use crippled encryption algorithms to protect their data and financial transactions.

Still, we may be in for interesting times...