Soon after September 11, 2001, Eli Pariser built a website calling for a peaceful approach to fighting terrorism. He quickly found himself in contact with more than 500,000 people -- and an unexpected leader within the burgeoning online peace movement. He soon joined with MoveOn.org to spearhead an anti-war campaign, and in 2004 he became MoveOn's executive director.

In 2009, suspecting that the internet might harbor hidden threats to democracy, Pariser wrote The Filter Bubble, exposing how algorithms amplify select ideas while making others invisible. In 2012, he cofounded Upworthy as a platform to direct millions of users to high-quality discourse around progressive issues. In 2017, he joined New America (where he is currently an Omidyar Fellow) to help create democracy-friendly spaces in the digital landscape.