The Web's New Gold Mine: Your Secrets

A Journal investigation finds that one of the fastest-growing businesses on the Internet is the business of spying on consumers. First in a series.

By JULIA ANGWIN
WSJ

Hidden inside Ashley Hayes-Beaty's computer, a tiny file helps gather personal details about her, all to be put up for sale for a tenth of a penny.

The file consists of a single code— 4c812db292272995e5416a323e79bd37—that secretly identifies her as a 26-year-old female in Nashville, Tenn.

The code knows that her favorite movies include "The Princess Bride," "50 First Dates" and "10 Things I Hate About You." It knows she enjoys the "Sex and the City" series. It knows she browses entertainment news and likes to take quizzes.

"Well, I like to think I have some mystery left to me, but apparently not!" Ms. Hayes-Beaty said when told what that snippet of code reveals about her. "The profile is eerily correct."

(More here.)