The US government plans to track all of its citizens through transaction records. Which- if you ignore the civil liberties, technical and legal worries- seems like a great idea. Until you apply a couple of minutes thought to it, which seems to be a minute and a half more than the US government has. People wanting to commit crimes will take to paying cash, doing barter deals- buy something innocuous and use it in trade for the car or gun they really want- or bluffing the criteria by buying return tickets for their one way flight.

Another factor is that everyone makes ‘strange’ purchases from time to time. The tourist who goes to the shooting range (as I plan to when I’m in the USA), the student flying across country to hitch back or the person who hires a car just to go for a drive. Are they going to investigate every one of these, or filter them out based on profiling? I can just imagine the criteria- ‘[Age]=18 AND [Purchases_Music]=’Marilyn Manson’ AND [Relatives]![Purchases_Gun]=True’

The supporters say that commercial entities already hold this sort of information. They may, but they are using it for marketing- a data set that large isn’t for tracking down individuals, it’s for following trends. The corporate folks have the power to junk mail you- which is quite evil- but they are held short of investigating people and potentially destroying your (innocent) life.