The internet is full of opportunities to make money. Unfortunately, one of the best ways to make money is collecting private information. A rising problem is Facebook. Users of Facebook are giving away a ton of information and most people don't even know they're doing it. Facebook is gathering a lot of information, whether it'd be your demographics or the things you like. Information that is unique and information advertisers would love to get a hold of.
Another example would be the one that was discussed in the book. Google bought this company called Neven Vison which specializes in analyzing and reading facial expressions. This would be great information to buy as well, as advertisers would love to see how their consumers react to ads or webpages, be it a smile or a frown. There is a lot of controversy behind this as people are generally not to keen on having their facial expression read to the benefit of advertising.
Privacy infringement is a growing concern, and the internet is adding fuel to the fire.