(NBC) - If you get nervous or paranoid about being followed while you're surfing the web, chances are you have reason to be.
Researchers at the University of Washington in Seattle looked at web tracking over the last 20 years and found at least 75 percent of the world's 500 most popular websites contain web trackers.
That figure was less than 5 percent back in 1998.
Researchers also found half of those top 500 websites contained at least four third-party trackers.
Courtesy: NBC News Channel