As far as I am concerned it is still an invasion of privacy. I dont want some machine to record and store information on every movie I ever watch. Besides that who is to say what is illegal and what isn't, Kocher says it himself,
If somebody makes a copy of a complete work, you can trace that back to the device that was used. But if you're not making a copy, or if you're making copies and only using them within your house or even giving them to a friend who doesn't distribute them, then there's no record of what happens.
What if I have a huge amount of friends, and those friends have friends, would that be considered illegal. Give me a break.