The Wall Street Journal has added a investigative series to their blog titled What They Know. Sounds sufficiently scary.
I think this is noteworthy for two reasons. First, its a sign that the intersection of privacy and marketing is no longer an issue just for law geeks. Second, the blog seems to have done a fairly good job of visualizing how data is used by third parties.
It will probably surprise many to see that something as seemingly innocuous as online dictionaries can be used to collect so much information about people.