Founded the nonprofit document archive and disclosure WikiLeak

WikiLeaks is an international non-profit organisation that publishes news leaks and classified media provided by anonymous sources. Its website, initiated in 2006 in Iceland by the organisation Sunshine Press, claimed in 2016 to have released online 10 million documents in its first 10 years. Julian Assange, an Australian Internet activist, is generally described as its founder and director. Since September 2018, Kristinn Hrafnsson has served as its editor-in-chief.

The group has released a number of prominent document caches. Early releases included documentation of equipment expenditures and holdings in the Afghanistan war, a report informing a corruption investigation in Kenya, and a manual for operations at the U.S. prison at Guantanamo Bay, Cuba. 

In April 2010, WikiLeaks released the Collateral Murder footage from the 12 July 2007 Baghdad airstrike in which Iraqi journalists were among those killed. Other releases in 2010 included the Afghan War Diary and the "Iraq War Logs". The latter allowed the mapping of 109,032 deaths in "significant" attacks by insurgents in Iraq that had been reported to Multi-National Force – Iraq, including about 15,000 that had not been previously published. 

In 2010, WikiLeaks also released the US State Department diplomatic "cables", classified cables that had been sent to the US State Department. In April 2011, WikiLeaks began publishing 779 secret files relating to prisoners detained in the Guantanamo Bay detention camp. In 2012, WikiLeaks released the "Syria Files," over two million emails sent by Syrian politicians, corporations and government ministries. 

In 2015, WikiLeaks published Saudi Arabian diplomatic cables, documents detailing spying by the U.S. National Security Agency on successive French Presidents, and the intellectual property chapter of the Trans-Pacific Partnership, a controversial international trade agreement which had been negotiated in secret.

During the 2016 US presidential election campaign, WikiLeaks released emails and other documents from the Democratic National Committee and from Hillary Clinton's campaign manager, John Podesta. These releases caused significant harm to the Clinton campaign, and have been attributed as a potential contributing factor to her loss. The U.S. intelligence community expressed "high confidence" that the leaked emails had been hacked by Russia and supplied to WikiLeaks, while WikiLeaks denied their source was Russia or any other state. During the campaign, WikiLeaks promoted conspiracy theories about Hillary Clinton and the Democratic Party. In private conversations from November 2015 that were later leaked, Julian Assange expressed a preference for a GOP victory in the 2016 election, explaining that "Dems+Media+liberals woudl then form a block to reign in their worst qualities. With Hillary in charge, GOP will be pushing for her worst qualities, dems+media+neoliberals will be mute." In further leaked correspondence with the Trump campaign on election day (8 November 2016), WikiLeaks encouraged the Trump campaign to contest the election results as being "rigged" should they lose.

In 2016, WikiLeaks released nearly 300,000 emails it described as coming from Turkey's ruling Justice and Development Party, later found to be taken from public mailing archives, and over 50,000 emails from the Turkish minister of energy. In 2017, WikiLeaks published internal CIA documents describing tools used by the agency to hack devices including mobile phones and routers.

WikiLeaks has drawn criticism for its alleged absence of whistleblowing on or criticism of Russia, and for criticising the Panama Papers' exposé of businesses and individuals with offshore bank accounts. The organization has additionally been criticised for inadequately curating its content and violating the personal privacy of individuals. WikiLeaks has, for instance, revealed Social Security numbers, medical information, credit card numbers and details of suicide attempts.