TCAP Expansion: TCAP to include James Mason content

Tech Against Terrorism’s Terrorist Content Analytics Platform (TCAP) is now including content produced by James Mason, an influential American neo-Nazi accelerationist ideologue. This addition aligns with our Inclusion Policy based on evolving global designations, and with our own analysis of the online threat posed by the violent far-right. Given James Mason wrote Siege(1), we deem this to be official content produced by a designated entity in scope, and therefore will alert this material to tech companies when we find it on their platforms. We will also alert any other form of content directly produced by Mason, as well as media content featuring Mason when it furthers his propaganda purposes.

Grounds for inclusion

On 25 June 2021, James Mason was listed by the Canadian government as a terrorist entity. The listing emphasises Mason’s operational connection to internationally designated neo-Nazi groups such as Atomwaffen Division (AWD) and the ideological influence of his book, Siege, on contemporary far-right terrorist movements. The TCAP already includes far-right terrorist entities designated by Canada including Blood and Honour, Combat 18, and Proud Boys, and we applaud Canada for providing this legal precedent and leading the way in designating far-right violent extremist groups and actors.

James Mason is the first in a series of terrorist entities we are adding to the TCAP in the upcoming months, as part of the larger expansion of our Inclusion Policy. New entity profiles will detail the evidence behind our decisions, to ensure the TCAP remains transparent and consistent with the rule of law. These profiles will also be available on Tech Against Terrorism's Knowledge Sharing Platform, alongside other resources and tools for improving online counterterrorism responses.

Classifying and verifying James Mason content

Consistent with the TCAP’s Classification and Verification Policy, online content relating to James Mason will be assessed by our OSINT experts based on the source and the content itself. In terms of the content itself, anything directly produced by James Mason will be in scope, including:

  • Individual newsletters, the full original publication, and new iterations of Siege (four editions in total)

  • Blog posts authored by Mason

  • Other essays, books and articles written by Mason

  • Online accounts operated by Mason

  • Videos and podcasts produced by Mason

  • Direct excerpts from Mason’s publications in scope- either in picture, message, video or audio formats

For content not directly authored by Mason, the source, in addition to the content itself, should be assessed to determine its purpose. For example, we will include:

  • Media appearances of Mason on far-right extremist outlets that aim to further his own propaganda purposes

  • ‘Siege culture’ content that contains quotations from Mason’s publications in scope


James Mason has been an active neo-Nazi since he joined the American Nazi Party in 1966.(2) He is best known for producing a monthly newsletter called Siege from 1980-1986, which was later amalgamated and published as a book by Michael Moynihan’s Storm Books in 1992.(3) Siege advocates for the rejection of traditional politics in any form, instead promoting total societal breakdown through political violence. Self-directed terrorism is encouraged as part of an ‘accelerationist’(4) logic, where terrorist violence can accelerate the collapse of liberal, democratic societies by triggering apocalyptic race wars.

It is only in the last 10 years that Mason’s works have been popularised by supporters, inspiring a transnational spike in neo-Nazi militancy.(5) Following the adaptation of Siege content by users on the Iron March forum(6) around 2016, a wider, largely digital phenomenon emerged known as ‘Siege culture’. This content, often in the form of memes or ‘fashwave’(7) posters, is distinctive in its promotion of sadistic violence (including Brenton Tarrant, Dylann Roof etc.) and Nazi aesthetic (white, red, black).

Connections to far-right violent extremism and terrorism

James Mason himself has re-engaged with this new generation of neo-Nazis, establishing connections with the leadership of Atomwaffen Division (AWD) and writing 41 new pieces for the Siege Culture website in 2017/18. AWD, an organisation designated by multiple democratic nations(8), draws direct inspiration from Siege material for its own propaganda and has posted images of members alongside James Mason.(9) AWD inspired likeminded cells across Europe including Sonnenkrieg Division in the UK (designated by the UK government February 2020) and Atomwaffen Deutschland, and its members have been linked to five murders in the US.(10) Based on our analysis, Mason remains active within these communities as he continues to publish new essays online and appears in videos, interviews and podcasts.

We assess Siege content to glorify, incite, and encourage terrorism, and based on this and Mason’s designation, we will now begin alerting this content to tech companies, allowing them to assess it against their own terms of service.

1 The book Siege is a collection of editorials from a monthly newsletter produced by James Mason from 1980-1986, which promotes neo-Nazism and lone-wolf terrorism. Since the original was published in 1992, there have been three more editions (2003, 2017, 2018) with new prefaces, appendices and added images.

2 'James Mason', Southern Poverty Law Center,

3 Bethan Johnson and Matthew Feldman, 'Siege Culture After Siege: Anatomy of a Neo-Nazi Terrorist Doctrine', International Centre for Counter-Terrorism (ICCT),

4 For an in-depth explanation of militant accelerationism find an explanation by the Accelerationist Research Consortium (ARC) here and a dedicated Tech Against Terrorism podcast episode here.

5 Bethan Johnson and Matthew Feldman, 'Siege Culture After Siege: Anatomy of a Neo-Nazi Terrorist Doctrine', International Centre for Counter-Terrorism (ICCT),

6 Launched in September 2011, Iron March was a far-right Neo-Nazi web forum associated with user discussions around fascism and organised white supremacism.

7 Fashwave is a derivative aesthetic of Synthwave or Vaporwave, combining them with symbols associated with fascism, white supremacy and white nationalism.

8 Atomwaffen division is designated by Canada, and the UK

9 'James Mason', Southern Poverty Law Center,

10 Bethan Johnson and Matthew Feldman, 'Siege Culture After Siege: Anatomy of a Neo-Nazi Terrorist Doctrine', International Centre for Counter-Terrorism (ICCT),