48. Pierre Omidyar
Omidyar is joining the fight against fake news. In April, his philanthropic investment firm Omidyar Network announced a $100 million commitment to support investigative reporting and fight hate speech. Omidyar founded ebay at age 28 and stepped down as chairman in 2015 but remains on the board. Omidyar met his wife, Pam, who cofounded Omidyar Network, at Tufts, where he studied computer science and she studied biology.