Google sends vehicles around to take photos of everyone's homes and streets, etc., for it's street view maps. The vehicles were recently discovered (in Germany, but you know they were doing it everywhere) to be simultaneously performing illegal surveillance and recording of the data on computers inside those homes. Says the NY Times, 5/15/10:
http://www.nytimes.com/2010/05/16/technology/16google.html?scp=2&sq=google&st=cse What use they could make with the data they were caught collecting is unknown, but they were performing illegal rolling wiretaps basically, of every house they drove past and photographed. It is interesting that the technology exists for this, and I never trusted their photographic drive bys. It's a private, for profit, big brother.
The governments have to know everything about us for 'national security'. On the other hand, the reason why citizens can't get any info on their own govs' actions, is 'national security'.
Ben Franklin's quote on trading freedom for temporary safety seems relevant.