You're assuming that Facebook or Google sold your private data to third parties. While this is theoretically possible, it is unlikely, for both practical and et

You're assuming that Facebook or Google sold your private data to third parties. While this is theoretically possible, it is unlikely, for both practical and ethical reasons. I notice you say you bought baby-related products with your credit card. This provides a more likely explanation: statistical analysis of consumer buying habits by retailers (doesn't even have to be the card company) can reveal many sorts of information. The particular example of pregnancy has been well-covered, see http://www.nytimes.com/2012/02/19/magazine/shopping-habits.html http://www.nytimes.com/2012/02/19/magazine/shopping-habits.h... and http://consumerist.com/2012/02/17/target-figures-out-teen-girl-is-pregnant-before-her-father-does-sends-helpful-coupons/ http://consumerist.com/2012/02/17/target-figures-out-teen-gi... . As for your examples: I'd say that while #1 and #2 are targeted advertisements, #3 is not an advertisement, it's straight-up espionage.