NSLs aren't the only way the government can get at corporate data. Sometimes they simply purchase it, just as any other company might. Sometimes they can get it for free, from corporations that want to stay on the government's good side.

CISPA, a bill currently wending its way through Congress, codifies this sort of practice even further. If signed into law, CISPA will allow the government to collect all sorts of personal data from corporations, without any oversight at all, and will protect corporations from lawsuits based on their handing over that data. Without hyperbole, it's been called the death of the 4th Amendment. Right now, it's mainly the FBI and the NSA who are getting this data, but -- all sorts of government agencies have administrative subpoena power.

Data on this scale has all sorts of applications. From finding tax cheaters by comparing data brokers' estimates of income and net worth with what's reported on tax returns, to compiling a list of gun owners from Web browsing habits, instant messaging conversations, and locations -- did you have your iPhone turned on when you visited a gun store? -- the possibilities are endless.

Government photograph databases form the basis of any police facial recognition system. They're not very good today, but they'll only get better. But the government no longer needs to collect photographs. Experiments demonstrate that the Facebook database of tagged photographs is surprisingly effective at identifying people. As more places follow Disney's lead in fingerprinting people at its theme parks, the government will be able to use that to identify people as well.

In a few years, the whole notion of a government-issued ID will seem quaint. Among facial recognition, the unique signature from your smart phone, the RFID chips in your clothing and other items you own, and whatever new technologies that will broadcast your identity, no one will have to ask to see ID. When you walk into a store, they'll already know who you are. When you interact with a policeman, she'll already have your personal information displayed on her Internet-enabled glasses.

Soon, governments won't have to bother collecting personal data. We're willingly giving it to a vast network of for-profit data collectors, and they're more than happy to pass it on to the government without our knowledge or consent.