OSINT for Counterterrorism and Extremism

OSINT can help investigators establish the wider context in a counterterrorism investigation.

Publicly available information may reveal the development of an ideology, connections between online accounts, participation in extremist communities, changes in behaviour, travel, target selection, access to weapons or materials and relationships with people already known to present a risk.

The UK government’s 2024 definition of extremism also acknowledges that most extremist activity does not meet a terrorism or national-security threshold. Extremism, radicalisation, hate crime, public disorder and terrorism overlap in places, but they are not interchangeable.

OSINT should therefore help investigators answer a more precise question: Does the available information indicate ideology alone, vulnerability to radicalisation, support for terrorism, or movement towards violent action?

Understanding Terrorism and Extremism

Section 1 of the Terrorism Act 2000 defines terrorism through several connected elements.

The use or threat of action must generally be designed to influence the government or an international governmental organisation, or intimidate the public or a section of the public. It must be made for the purpose of advancing a political, religious, racial or ideological cause.

The relevant action may involve:

• Serious violence against a person
• Serious damage to property
• Endangering another person’s life
• Creating a serious risk to public health or safety
• Seriously interfering with or disrupting an electronic system

Where firearms or explosives are involved, the requirement that the action be designed to influence government or intimidate the public does not apply in the same way.

Extremism has a different status. The UK government’s 2024 definition of extremism concerns the advancement of an ideology based on violence, hatred or intolerance that aims to negate the fundamental rights and freedoms of others, undermine or replace the UK’s system of liberal parliamentary democracy, or intentionally create a permissive environment for others to do so.