TiVo tracks user information on an aggregate basis. This means that they know which parts of the show their users are reacting to on a second by second basis, but they don't know what you are personally doing. The Janet Jackson thing was kind of like porn. We all know that people love it, but don't really want to acknowledge it. TiVo's privacy policy allows them to know that people were watching it, but they can't tell if your one of seedy people who watched it.

As far as how far should it go. I'm not really sure, I think that should be left up to each user to decide. In Austrailia OpenTV tracks everything on a personal basis and replaces commercials based on demographics. This means if the girlfriend is coming over you need to be prepared to explain why girls gone wild keeps showing up. On one level I'm not sure if I would trust OpenTV enough to have this info, but on another level I think I would trust TiVo and would enjoy some of the benefits that targeted ads and personalization could bring.

TiVo has always been very concerned about their users rights and I'm sure that they would never try individual tracking without an owners consents. As far as what sort of fun facts TiVo tracks.

-The average TiVo user hits a button on their remote 357 times a day.
-70% of users watch time shifted content and 30% watch live
-Of the 70% that time shifts 30% of them don't fast forward through commercials
-People have a tendacy to watch sports live (duh) but there is a large user base who waits a half an hour first