 His 2018 book "Custodians of the Internet" discusses the complex relationship social media sites have with hate speech and extremist groups on their sites, as there are no defined "custodian" responsibilities in policing this content, and actions taken are mainly left up to the discretion of private companies.The article "The Politics of 'Platforms" by Tarleton Gillespie provides the information of how one word can provide many paths for an online content provider.He has grouped the word 'platform' into four distinct categories that can help define what an online software platform does.