Watching Studio60

I understand that the TV networks need to know how many people are watching the different shows, and that this information allows them to set the advertising rates for the various commercials as well as giving them insight into what America is watching, so they can provide better programming and set better schedules. However, what I find really scary, is that apparantly they can now not only track what we are watching real time, but also when we play back and watch shows that have been recorded on various DVR devices. How do they do that? If I record a program onto my DVR, and play it back at a later time, how do they track my playback? I don’t know about you but I find that very Big Brotherish, not to mention, intrusive.
However, the up side of that is that Studio 60 viewing numbers apparantly benefits from this intrusion, upping the viewing numbers every week - as this quote from Zap2it web site tells us:
“The first-year series from “West Wing” creator Aaron Sorkin is the most “time-shifted” series on television this season, according to ratings provider Nielsen. That means a greater percentage of its viewers record the show and watch it later than anything else on the broadcast networks.
At the beginning of 2006, Nielsen started tracking two different ratings systems as a way to measure the impact of digital video recorders. “Live plus same-day” ratings — the ones reported on Zap2it every morning — measure the number of people who watch a given show as it airs or within the next few hours. In “Studio 60’s” case, that number hovered around 8 million people for much of the fall.
Nielsen also tracks “live plus seven” ratings, which includes people who watch a recorded copy of a show within the next week. “Studio 60″ adds nearly 11 percent to its total audience in those ratings; including reruns, its average is closer to 9 million viewers for the season”

WHile I am delighted that more people are really watching the show, I am still freaked out by the thought that what I record and play back can be tracked. I would really like to know how they do that? Do THEY also know what DVD’s I rent and view? Do THEY know what I eat for breakfast or wear to bed? Is America really becoming a Big Brother nation, or has it been all along and I was just blissfully unaware?