I was listening to On The Media, a weekly NPR show/podcast, and heard a retelling by Sam Thielman of the Guardian of what I always thought was an apocryphal tale regarding data mining by Target Corporation (starts at about 5:00):
A young woman's father kept getting flyers for diapers and baby food. He finally go so mad, he went to the local Target and said "please stop sending these to my 16-year-old daughter; she's not pregnant." It turned out that the company had in fact been logging her purchases of stuff like folic acid, and understood that through her purchase history that she was pregnant. They knew before her dad did.
- Forbes - How Target Figured Out A Teen Girl Was Pregnant Before Her Father Did: localizes the story as being near Minneapolis, Minnesota
- Slate - What’s Even Creepier Than Target Guessing That You’re Pregnant?
- NYT Magazine - How Companies Learn Your Secrets
- (for the UK crowd:) Daily Mail - How Target knows when its shoppers are pregnant - and figured out a teen was before her father did
Is this actually true? It seems strange that a 16-year-old would be as-easily tracked (rare, but not impossible to have a credit card, or some sort of "rewards" card).