We will focus on the development of public-private partnerships to facilitate and scale public-led campaigns against prejudice, online hate and extremism, including ISIS. Peer to Peer: Challenging Extremism (P2P) is a partnership among Facebook, U.S. Department of Homeland Security and EdVenture Partners. It harnesses the talent of university students around the globe to design and prototype credible and authentic counterspeech, social and digital media campaigns. We will share the successes and challenges of this model, explore further scaling and identify how other entities can become involved or use similar methodologies to challenge extremist narratives online.