To claim that monitoring buying habits is the equivelent of placing a camers in your bedroom is yello journalism at its prime. In reality it is more akin to looking at the store security camera. The web is a public space, just like the street downtown. Saying or doing something on the web is like shouting your message in a football stadium full of people. The only security is that they are all shouting at once and it is very difficult to hear one voice.
Encryption is no better than wispering in someones ear.
The message can still be intercepted and encryption has been broken. The only saving grace is that my remaining credit ballance is not enough to pay the electric bill for the CRAYs and PCs necessary to break it. The only way to remain anonymous on the web is to be creative, paranoid and somewhat anal about it. You have been warned. Tony Gore demons of the wired world.