Understanding and preventing internet-facilitated radicalisation

A laptop displaying a warning symbol

This paper reviews available research on how the internet facilitates radicalisation and measures to prevent it. It briefly canvasses evidence on the extent to which the internet contributes to radicalisation broadly, and who is most susceptible to its influence, before delving further into the mechanisms underpinning the relationship between the internet and violent extremism.

High-level approaches to combating internet-facilitated radicalisation, including content removal, account suspensions, reducing anonymity, and counternarrative and education campaigns, are mapped against these mechanisms. This illustrates how these approaches can disrupt radicalisation and assists researchers, policymakers and practitioners to identify potential gaps in existing counterterrorism and countering violent extremism regimes. Research on the implementation and outcomes of these approaches is also summarised.


URLs correct as at May 2023

Akbarzadeh S 2013. Investing in mentoring and educational initiatives: The limits of de-radicalisation programmes in Australia. Journal of Muslim Minority Affairs 33(4): 451–463. https://doi.org/10.1080/13602004.2013.866347

Alava S, Frau-Meigs D & Hassan G 2017. Youth and violent extremism on social media: Mapping the research. UNESCO Publishing. https://unesdoc.unesco.org/ark:/48223/pf0000260382

Ali S et al. 2021. Understanding the effect of deplatforming on social networks. Proceedings of the 13th ACM Web Science Conference 2021. Online event, UK: Association for Computing Machinery: 187–195. https://doi.org/10.1145/3447535.3462637

All Together Now 2022. Everyday racism. https://alltogethernow.org.au/our-work/everyday-racism/

Aly A, Balbi A & Jacques C 2015. Rethinking countering violent extremism: Implementing the role of civil society. Journal of Policing, Intelligence and Counter Terrorism 10(1): 3–13. https://doi.org/10.1080/18335330.2015.1028772

Ambrozik C 2019. Countering violent extremism globally: A new global CVE dataset. Perspectives on Terrorism 13(5): 102–111. https://www.jstor.org/stable/26798581

Atari M et al. 2022. Morally homogeneous networks and radicalism. Social Psychological and Personality Science 13(6): 999–1009. https://doi.org/10.1177/19485506211059329

Australian Government 2022. Safeguarding our community together: Australia’s counter-terrorism strategy. Canberra: Department of Home Affairs. https://www.nationalsecurity.gov.au/what-australia-is-doing/a-national-approach/australias-counter-terrorism-strategies

Bastug MF, Douai A & Akca D 2020. Exploring the “demand side” of online radicalization: Evidence from the Canadian context. Studies in Conflict & Terrorism 43(7): 616–637. https://doi.org/10.1080/1057610X.2018.1494409

Bélanger JJ, Nisa CF, Schumpe BM, Gurmu T, Williams MJ & Putra IE 2020. Do counter-narratives reduce support for ISIS? Yes, but not for their target audience. Frontiers in Psychology 11: 1–11. https://doi.org/10.3389/fpsyg.2020.01059

Berger JM & Perez H 2016. The Islamic State’s diminishing returns on Twitter: How suspensions are limiting the social networks of English-speaking ISIS supporters. George Washington University. https://extremism.gwu.edu/isis-online-reports

Bodine-Baron E, Marrone JV, Helmus TC & Schlang D 2020. Countering violent extremism in Indonesia: Using an online panel survey to assess a social media counter-messaging campaign. Santa Monica, California: RAND Corporation. https://www.rand.org/pubs/research_reports/RRA233-1.html

Borum R 2003. Understanding the terrorist mind-set. Crime & Justice International 19(77): 28–30. https://www.ojp.gov/ncjrs/virtual-library/abstracts/understanding-terrorist-mindset

Braddock K & Horgan J 2016. Towards a guide for constructing and disseminating counternarratives to reduce support for terrorism. Studies in Conflict & Terrorism 39(5): 381–404. https://doi.org/10.1080/1057610X.2015.1116277

Bradford B et al. 2019. Report of the Facebook Data Transparency Advisory Group. New Haven: Justice Collaboratory: Yale Law School. https://www.justicehappenshere.yale.edu/reports/report-of-the-facebook-data-transparency-advisory-group

Briggs R & Feve S 2013. Review of programs to counter narratives of violent extremism: What works and what are the implications for government? London: Institute for Strategic Dialogue. https://www.publicsafety.gc.ca/lbrr/archives/cn28580-eng.pdf

Bright J 2017. Explaining the emergence of echo chambers on social media: The role of ideology and extremism. https://ssrn.com/abstract=2839728

Brouillette-Alarie S et al. 2022. Systematic review on the outcomes of primary and secondary prevention programs in the field of violent radicalization. Journal for Deradicalization 30: 117–168. https://journals.sfu.ca/jd/index.php/jd/article/view/577

Brown K & Marway H 2018. Preventing radicalisation to terrorism and violent extremism: Delivering counter‐ or alternative narratives. Radicalisation Awareness Network

Brzuszkiewicz S 2020. Jihadism and far-right extremism: Shared attributes with regard to violence spectacularisation. European View 19(1): 71–79. https://doi.org/10.1177/1781685820915972

Carthy SL, Doody CB, Cox K, O’Hora D & Sarma KM 2020. Counter‐narratives for the prevention of violent radicalisation: A systematic review of targeted interventions. Campbell Systematic Reviews 16(3): e1106. https://doi.org/10.1002/cl2.1106

Chandrasekharan E, Pavalanathan U, Srinivasan A, Glynn A, Eisenstein J & Gilbert E 2017. You can’t stay here: The efficacy of Reddit’s 2015 ban examined through hate speech. Proceedings of the ACM Human-Computer Interaction 1(31): 1–22. https://doi.org/10.1145/3134666

Chang J 2008. The role of anonymity in deindividuated behavior: A comparison of deindividuation theory and the social identity model of deindividuation effect. The Pulse 6(1): 1–8

Conway M, Scrivens R & McNair L 2019. Right-wing extremists’ persistent online presence: History and contemporary trends. International Centre for Counter-Terrorism Policy Brief. The Hague: International Centre for Counter-Terrorism. https://www.icct.nl/publication/right-wing-extremists-persistent-online-presence-history-and-contemporary-trends

Counter Terrorism Policing 2018. Together we’re tackling online terrorism. Counter Terrorism Policing News, December 2018. https://www.counterterrorism.police.uk/together-were-tackling-online-terrorism/

Dalgaard-Nielsen A 2016. Countering violent extremism with governance networks. Perspectives on Terrorism 10(6): 135–139. https://www.jstor.org/stable/26297713

Dalgaard-Nielsen A 2008. Studying violent radicalization in Europe II: The potential contribution of socio-psychological and psychological approaches. Working Paper no 2008/3. Copenhagen: Danish Institute for International Studies. https://www.econstor.eu/bitstream/10419/84593/1/DIIS2008-03.pdf

Davies L 2018. Review of educational initiatives in counter-extremism internationally: What works? Gothenburg: Segerstedt Institute University of Gothenburg. https://gupea.ub.gu.se/handle/2077/66726

della Porta D & LaFree G 2012. Processes of radicalization and deradicalization. International Journal of Conflict and Violence 6(1): 4–10

Demetriou C & Silke A 2003. A criminological internet ‘sting’: Experimental evidence of illegal and deviant visits to a website trap. British Journal of Criminology 43(1): 213–222. https://doi.org/10.1093/bjc/43.1.213

Desmarais SL, Simons-Rudolph J, Brugh CS, Schilling E & Hoggan C 2017. The state of scientific knowledge regarding factors associated with terrorism. Journal of Threat Assessment and Management 4(4): 180–209. https://doi.org/10.1037/tam0000090

Díaz Á & Hecht-Felella L 2021. Double standards in social media content moderation. New York: Brennan Center for Justice at New York University School of Law. https://www.brennancenter.org/our-work/research-reports/double-standards-social-media-content-moderation

Doosje B, Moghaddam FM, Kruglanski AW, De Wolf A, Mann L & Feddes AR 2016. Terrorism, radicalization and de-radicalization. Current Opinion in Psychology 11: 79–84. https://doi.org/10.1016/j.copsyc.2016.06.008

Droogan J, Waldek L & Blackhall R 2018. Innovation and terror: An analysis of the use of social media by terror-related groups in the Asia Pacific. Journal of Policing, Intelligence and Counter Terrorism 13(2): 170–184. https://doi.org/10.1080/18335330.2018.1476773

Dwoskin E & Timberg C 2019. Christchurch mosque shootings: Inside YouTube’s struggles to shut down video – and the humans who outsmarted its systems. Washington Post, 18 March. https://www.washingtonpost.com/technology/2019/03/18/inside-youtubes-struggles-shut-down-video-new-zealand-shooting-humans-who-outsmarted-its-systems/

Freear M & Glazzard A 2020. Preventive communication: Emerging lessons from participative approaches to countering violent extremism in Kenya. The RUSI Journal 165(1):90–106. https://doi.org/10.1080/03071847.2020.1734316

Frissen T 2021. Internet, the great radicalizer? Exploring relationships between seeking for online extremist materials and cognitive radicalization in young adults. Computers in Human Behavior 114: 106549. https://doi.org/10.1016/j.chb.2020.106549

Gaudette T, Scrivens R & Venkatesh V 2022. The role of the internet in facilitating violent extremism: Insights from former right-wing extremists. Terrorism and Political Violence 34(7): 1339–1356. https://doi.org/10.1080/09546553.2020.1784147

Gielen A 2019. Countering violent extremism: A realist review for assessing what works, for whom, in what circumstances, and how? Terrorism and Political Violence 31(6): 1149–1167. https://doi.org/10.1080/09546553.2017.1313736

Gill P 2015. Lone actor terrorists: A behavioural analysis. Oxford: Routledge

Gill P, Corner E, Conway M, Thornton A, Bloom M & Horgan J 2017. Terrorist use of the internet by the numbers: Quantifying behaviors, patterns, and processes. Criminology & Public Policy 16(1): 99–117. https://doi.org/10.1111/1745-9133.12249

Global Internet Forum to Counter Terrorism (GIFCT) 2022. GIFCT’s Hash-Sharing Database. https://gifct.org/hsdb/

Hafez M & Mullins C 2015. The radicalization puzzle: A theoretical synthesis of empirical approaches to homegrown extremism. Studies in Conflict & Terrorism 38(11): 958–975. https://doi.org/10.1080/1057610X.2015.1051375

Hall M, Logan M, Ligon GS & Derrick DC 2020. Do machines replicate humans? Toward a unified understanding of radicalizing content on the open social web. Policy & Internet 12(1): 109–138. https://doi.org/10.1002/poi3.223

Hamid N & Ariza C 2022. Offline versus online radicalization: Which is the bigger threat? Tracing outcomes of 439 jihadist terrorists between 2014–2021 in 8 Western countries. Global Network on Extremism and Technology. https://gnet-research.org/2022/02/21/offline-versus-online-radicalisation-which-is-the-bigger-threat/

Hardy K 2022. A crime prevention framework for CVE. Terrorism and Political Violence 34(3): 633–659. https://doi.org/10.1080/09546553.2020.1727450

Hardy K 2018. Comparing theories of radicalisation with countering violent extremism policy. Journal for Deradicalization 15: 76–110. https://journals.sfu.ca/jd/index.php/jd/article/view/150

Hassan G et al. 2018. Exposure to extremist online content could lead to violent radicalization: A systematic review of empirical evidence. International Journal of Developmental Science 12(1–2): 71–88. https://doi.org/10.3233/DEV-170233

Helmus TC & Klein K 2018. Assessing outcomes of online campaigns countering violent extremism: A case study of the Redirect Method. Santa Monica, CA: RAND Corporation. https://www.rand.org/pubs/research_reports/RR2813.html

Hollewell GF & Longpré N 2021. Radicalization in the social media era: Understanding the relationship between self-radicalization and the internet. International Journal of Offender Therapy and Comparative Criminology 66(8): 896–913. https://doi.org/10.1177/0306624X211028771

Jensen MA, Atwell AA & James PA 2020. Radicalization to violence: A pathway approach to studying extremism. Terrorism and Political Violence 32(5): 1067–1090. https://doi.org/10.1080/09546553.2018.1442330

Kenyon J, Binder JF & Baker‐Beall C 2023. Online radicalization: Profile and risk analysis of individuals convicted of extremist offences. Legal and Criminological Psychology 28(1): 74–90. https://doi.org/10.1111/lcrp.12218

Kruglanski AW, Gelfand MJ, Bélanger JJ, Shevland A, Hetiarachcho M & Gunaratna R 2014. The psychology of radicalization and deradicalization: How significance quest impacts violent extremism. Political Psychology 35(1): 69–93. https://doi.org/10.1111/pops.12163

Kruglanski AW, Jasko K, Webber D, Chernikova M & Molinario E 2018. The making of violent extremists. Review of General Psychology 22(1): 107–120. https://doi.org/10.1037/gpr0000144

Kundnani A & Hayes B 2018. The globalisation of countering violent extremism policies: Undermining human rights, instrumentalising civil society. Amsterdam: Transnational Institute. https://www.tni.org/en/publication/the-globalisation-of-countering-violent-extremism-policies

LaFree G, Jensen MA, James PA & Safer-Lichtenstein A 2018. Correlates of violent political extremism in the United States. Criminology 52(2): 233–268. https://doi.org/10.1111/1745-9125.12169

Lindekilde L, Malthaner S & O’Connor F 2019. Peripheral and embedded: Relational patterns of lone-actor terrorist radicalization. Dynamics of Asymmetric Conflict: Pathways toward Terrorism and Genocide 12(1): 20–41. https://doi.org/10.1080/17467586.2018.1551557

Living Safe Together 2015. Preventing violent extremism and radicalisation in Australia. Canberra: Australian Government Attorney-General’s Department. https://www.livingsafetogether.gov.au/resources

Luca S 2022. In defense of online anonymity. Wall Street Journal, 17 June. https://www.wsj.com/articles/the-value-of-online-anonymity-11655473116

Macdonald S & Whittaker J 2019. Online radicalization: Contested terms and conceptual clarity. In JR Vacca (ed), Online terrorist propaganda, recruitment, and radicalization. Boca Raton: CRC Press. https://cronfa.swan.ac.uk/Record/cronfa45970

Mastroe C & Szmania S 2016. Surveying CVE metrics in prevention, disengagement and deradicalization programs. Report to the Office of University Programs, Science and Technology Directorate. College Park, MD: Department of Homeland Security. https://www.start.umd.edu/publication/surveying-cve-metrics-prevention-disengagement-and-de-radicalization-programs

McCauley C & Moskalenko S 2017. Understanding political radicalization: The two-pyramids model. American Psychologist 72(3): 205–216. https://doi.org/10.1037/amp0000062

Meleagrou-Hitchens A, Alexander A & Kaderbhai N 2017. The impact of digital communications technology on radicalization and recruitment. International Affairs 93(5): 1233–1249. https://doi.org/10.1093/ia/iix103

Mølmen GN & Ravndal JA 2021. Mechanisms of online radicalisation: how the internet affects the radicalisation of extreme-right lone actor terrorists. Behavioral Sciences of Terrorism and Political Aggression. https://doi.org/10.1080/19434472.2021.1993302

Montrond A, Ekström A, Nielson R, Hadji-Janev M & Savoia E 2022. Comparative analysis of CT/CVE policies: USA, Canada, United Kingdom, Sweden, and North Macedonia. Homeland Security Affairs 18(1). https://doi.org/10.3390/proceedings2021077006

Muro D & Wilson T (eds) 2022. Contemporary terrorism studies. Oxford University Press. https://doi.org/10.1093/hepl/9780198829560.001.0001

Neo LS 2016. An internet-mediated pathway for online radicalisation: RECRO. In M Khader, LS Neo, G Ong, ET Mingyi & J Chin (eds), Combating violent extremism and radicalization in the digital era. Hershey, PA: IGI Global: 197–224. https://doi.org/10.4018/978-1-5225-0156-5.ch011

Neo LS, Dillon L & Khader M 2017. Identifying individuals at risk of being radicalised via the internet. Security Journal 30: 1112–1133. https://doi.org/10.1057/s41284-016-0080-z

Neo LS, Dillon L, Shi P, Tan J, Wang Y & Gomes D 2016. Understanding the psychology of persuasive violent extremist online platforms. In M Khader, LS Neo, G Ong, ET Mingyi & J Chin (eds), Combating violent extremism and radicalization in the digital era. Hershey, PA: IGI Global: 1–15. https://doi.org/10.4018/978-1-5225-0156-5.ch001

Neumann P 2013. Options and strategies for countering online radicalization in the United States. Studies in Conflict & Terrorism 36(6): 431–459. https://doi.org/10.1080/1057610X.2013.784568

Pauwels L & Schils N 2016. Differential online exposure to extremist content and political violence: Testing the relative strength of social learning and competing perspectives. Terrorism and Political Violence 28(1): 1–29. https://doi.org/10.1080/09546553.2013.876414

Robinson N & Whittaker J 2021. Playing for hate? Extremism, terrorism, and videogames. Studies in Conflict and Terrorism. Advance online publication. https://doi.org/10.1080/1057610X.2020.1866740

Rosand E & Winterbotham E 2019. Do counter-narratives actually reduce violent extremism? The Brookings Institution. https://www.brookings.edu/blog/order-from-chaos/2019/03/20/do-counter-narratives-actually-reduce-violent-extremism/

Rusumanov V 2016. The use of the internet by terrorist organizations. Information & Security 34(2): 137–150. https://doi.org/10.11610/isij.3409

Sageman M 2004. Understanding terror networks. Philadelphia: University of Pennsylvania Press. https://doi.org/10.9783/9780812206791

Saifudeen OA 2014. The cyber extremism orbital pathways model. Singapore: S Rajaratnam School of International Studies, Nanyang Technological University

Schmitt JB, Rieger D, Ernst J & Roth H 2018. Critical media literacy and Islamist online propaganda: The feasibility, applicability and impact of three learning arrangements. International Journal of Conflict and Violence 12: 1–19. https://doi.org/10.4119/UNIBI/ijcv.642

Scott CR 2004. Benefits and drawbacks of anonymous online communication: Legal challenges and communicative recommendations. Free Speech Yearbook 41(1): 127–141. https://doi.org/10.1080/08997225.2004.10556309

Scrivens R & Conway M 2020. The roles of ‘old’ and ‘new’ media tools and technologies in the facilitation of violent extremism and terrorism. In R Leukfeldt & TJ Holt (eds), The human factor of cybercrime. Abingdon: Routledge. https://doi.org/10.4324/9780429460593-13

Spalek B 2016. Radicalisation, de-radicalisation and counter-radicalisation in relation to families: Key challenges for research, policy and practice. Security Journal 29(1): 39–52. https://doi.org/10.1057/sj.2015.43

Speckhard A, Shajkovci A & Ahmed M 2018. Intervening in and preventing Somali-American radicalization with counter narratives. Journal of Strategic Security 11(4): 32–71. https://doi.org/10.5038/1944-0472.11.4.1695

Strindberg A 2020. Social identity theory and the study of terrorism and violent extremism. Sweden: Swedish Defence Research Agency

United Nations 2015. Plan of action to prevent violent extremism. New York: United Nations. https://www.un.org/counterterrorism/plan-of-action-to-prevent-violent-e…

Valentini D, Lorusso AM & Stephan A 2020. Onlife extremism: Dynamic integration of digital and physical spaces in radicalization. Frontiers in Psychology 11: 524. https://doi.org/10.3389/fpsyg.2020.00524

Weimann G & Von Knop K 2008. Applying the notion of noise to countering online terrorism. Studies in Conflict & Terrorism 31(10): 883–902. https://doi.org/10.1080/10576100802342601

Whittaker J 2022. Rethinking online radicalization. Perspectives on Terrorism 16(4): 27–40.

Whittaker J 2020. Online echo chambers and violent extremism. In SM Khasru (ed), The digital age, cyber space, and social media: The challenges of security & radicalization. Dhaka: IPAG: 129–150

Winter C, Neumann P, Meleagrou-Hitchens A, Ranstorp M, Vidino L & Fürst J 2020. Online extremism: Research trends in internet activism, radicalization, and counter-strategies. International Journal of Conflict and Violence 14(2): 1–20. https://doi.org/10.4119/ijcv-3809

Wolfowicz M, Hasisi B & Weisburd D 2022. What are the effects of different elements of media on radicalization outcomes? A systematic review. Campbell Systematic Reviews 18(2): e1244. https://doi.org/10.1002/cl2.1244

Wolfowicz M, Litmanovitz Y, Weisburd D & Hasisi B 2020. A field-wide systematic review and meta-analysis of putative risk and protective factors for radicalization outcomes. Journal of Quantitative Criminology 36(3): 407–447. https://doi.org/10.1007/s10940-019-09439-4