The machines are getting smarter: a Wall Street Journal investigation peels back the curtain on a booming invasive online business in which tracking technology on popular websites access users’ information and compiles profiles—that are then bought and sold in bulk, or individually by data exchange companies. According to the study, the country's top 50 websites installed an average of 64 tracking technologies onto users' computers unknown to those clicking around on Wikipedia or Dictionary.com. New technologies can track people's web activity in real time and even ascertain a user's income level, location and medical conditions. This info has become a cash cow for companies who sell to advertisers who want to target and follow specific users across the Internet, tailoring messages specifically to them. "It is a sea change in the way the industry works," said a CEO of a data exchange company. "Advertisers want to buy access to people, not Web pages."