An anonymous reader writes: A study based on test results from 300,000 internet users "found significant degradations on the networks of the five largest internet service providers" in the United States. This group includes Time Warner Cable, Verizon, and AT&T. "The study, supported by the technologists at Open Technology Institute's M-Lab, examines the comparative speeds of Content Delivery Networks (CDNs), which shoulder some of the data load for popular websites. ... In Atlanta, for example, Comcast provided hourly median download speeds over a CDN called GTT of 21.4 megabits per second at 7pm throughout the month of May. AT&T provided speeds over the same network of of a megabit per second." These findings arrive shortly after the FCC's new net neutrality rules took effect across the U.S.