This is related to my series on web anonymity and how privacy does not exist online (part 1, part 2, part 3).
It’s a video by Dan Frankowski with wonderful examples of how information can be tied together to find out who you are even when information was supposed to be private.
Very well done, worth taking the time to watch if this interests you. Only starts getting really geeky and technical after around the 13 minute mark. Before that are some great examples of why this is an issue, and why this is important.