Former MoveOn.org executive director Eli Pariser isn't so sure that the Internet is breaking down information barriers. In his new book "The Filter Bubble," he writes of a hidden rise of personalization on the web and how it limits the information we access. This information, he suggests, then becomes our own unique web universe, or "filter bubble."

• More: About the book "The Filter Bubble: What the Internet Is Hiding From You" - at Amazon.com