Facing Privacy Issues: Your Face as Big Data

In the near future, a man who has an overdue book will walk into a library. A librarian behind a desk will get an alert on her mobile phone, tablet, or computer screen. After waiting a moment for him to approach the counter or place the book in a drop, she follows him to the stacks when he doesn’t. “Excuse me, Mr. Smith?” she says. “Our system shows you have a book overdue. Did you happen to bring it with you today?”