4chan is an anonymous English-language imageboard website. Launched by Christopher "moot" Poole in October 2003, the site hosts boards dedicated to a wide variety of topics, from video games and television to literature, cooking, weapons, music, history, anime, fitness, politics, and sports, among others. Registration is not available and users typically post anonymously. As of 2022, 4chan receives more than 22 million unique monthly visitors, of which approximately half are from the United States.

Anonymous is a decentralized international activist and hacktivist collective and movement primarily known for its various cyberattacks against several governments, government institutions and government agencies, corporations and the Church of Scientology.