James Mason is best known as the author of Siege, a newsletter and book advocating for radical violence and since-dubbed accelerationist strategies in the name of National Socialism. Mason became a controversial figure in neo-Nazi networks in the 1980s and 90s for his advocacy of violent terrorism, his writings praising Charles Manson, and allegations that he sexually groomed teenage girls (Mason was arrested twice for sexual exploitation of a minor).

Though not as common as references to his written work, Mason’s likeness is sometimes used in accelerationist neo-Nazi memes to signal support for his ideology and strategies. He also appears in memes invoking themes of pedophilia and rape (referencing his alleged history of preying on teenage girls) in order to shock viewers.

Mason is listed as a terrorist entity by Public Safety Canada.