By Chris Johnson, CEO, Cyacomb

It’s been 25 years since the world stood still and watched in horror as the 9/11 terrorist attacks unfolded.

The attacks were orchestrated with precision, carefully timed and devastating in their impact.

Since that dark, blue-skied day in September 2001, the world has witnessed several other devastating terrorist attacks. From the 7/7 attacks in London to the Madrid train bombings, terrorism has never faltered in the threat it poses to societies.

However, what has changed is the way terrorists operate and how people can become exposed to extremist ideas.

In 2001, smartphones didn’t exist, social media was in its infancy and encrypted consumer messaging was not part of everyday life. Communications relied heavily on landlines, basic mobile phones and face-to-face interactions.

Today, people can communicate instantly with anyone, regardless of where they are in the world. Social media allows information to reach huge audiences in seconds, while private and encrypted channels offer places for conversations to take place under the radar of law enforcement.

Unsurprisingly, terrorists and extremists have taken advantage of these advancements.

Radicalisation in a digital age

One of the biggest changes over the past 25 years is not just how terrorists communicate, but how extremist material can reach people.

In the past, radicalisation relied more heavily on physical networks, personal introductions, face-to-face interactions. Geography was the natural barrier.

Today, technology has completely changed this.

Extremist material can appear across social media, forums, gaming environments, private groups and encrypted channels. It can be presented as news, humour, grievance or a sense of belonging, exposing people to extremist narratives without them actively looking for terrorist material.

Technology has made extremist material easier to access, easier to distribute and easier to place in front of large audiences. It can also connect individuals with online communities that reinforce those views.

Recent advancements in generative AI amplifies the problem further, making it easier to create, translate and adapt content for different audiences.

How technology supports modern terrorism

The terrorists behind 9/11 went to significant lengths to keep their plans secret, often resorting to face-to-face meetings to remain under the radar.

However, communicating in this way also had limitations. Planning such a major attack took years, involved physical meetings and required extensive travel, time and money. It’s estimated the 9/11 attacks cost around $400,000 - $500,000 to carry out.

Today, technology has removed many of these limitations.

Mobile phones and online platforms allow people to communicate instantly across borders, while encryption can make conversations harder for law enforcement to access.

Someone researching a potential target also no longer has to spend hours manually searching online for information. AI can process large amounts of information quickly, potentially speeding up elements of reconnaissance and planning.

The threat has also become more fragmented. Organised terrorist groups and international networks remain a danger, but authorities must also deal with individuals who may be influenced remotely, move between different ideologies or have little direct contact with a formal terrorist organisation.

This creates a very different challenge for investigators.

One piece of information may appear insignificant on its own. But when it is connected with another device, person, account or investigation, it could become important.

The challenge is no longer simply gathering information. It is finding the information that matters.

Learning from the technology gaps of the past

One of the most difficult lessons from 9/11 and 7/7 is that there were pieces of intelligence available before both attacks.

The problem was understanding their significance.

Before 9/11, different US agencies held information relating to some of the eventual hijackers, but intelligence was fragmented across different systems and organisations.

Information that could have helped investigators build a clearer picture was not always shared or connected.

The 9/11 Commission subsequently identified serious weaknesses in the way information was shared and analysed. The FBI had limited capacity to share information internally and externally, while finding connections between individuals often required investigators to work through reports, photographs, telephone records and other intelligence.

This made it much harder for investigators to identify potential links.

Four years later, the 7/7 bombings demonstrated another challenge.

Two of the bombers, Mohammad Sidique Khan and Shehzad Tanweer, had previously appeared on the periphery of an MI5 investigation into other suspected extremists. At the time, however, they were not considered priority targets.

This wasn’t a case of the security services knowing they were planning an attack and deciding not to act.

Investigators were dealing with large numbers of people, pieces of intelligence and competing threats, and they had to decide where to focus their limited resources.

This is where technology can make a real difference today.

A person appearing briefly in one investigation might not seem significant. But if another piece of intelligence emerges months or years later, technology can make it easier to search data, identify links and bring potentially important information to an investigator’s attention.

This doesn’t mean technology would have prevented 9/11 or 7/7. It does, however, highlight how it can support future investigations by helping investigators identify and link critical information.

Finding the evidence that matters

Today, phones and computers are key sources of evidence in suspected terrorist investigations, but a single device can contain thousands of photographs, videos, messages, documents and other files.

Manually reviewing all of this information is an enormous task.

Technology can help investigators narrow that search.

Instead of manually reviewing every file stored on a device, matching technology can identify terrorist material that is already known to authorities.

This can dramatically reduce the amount of information an investigator needs to review and help them get to relevant evidence faster.

But finding terrorist material on a device does not prove that someone is a terrorist or intends to commit violence. A match is a piece of evidence that needs to be understood alongside everything else investigators know.

Importantly, matching can also be carried out without unnecessarily exposing everything else stored on the device.

Rather than opening and reviewing unrelated personal photographs, documents and other private information, technology can look specifically for matches against known terrorist material.

Investigators can find relevant content faster while reducing unnecessary access to information that has nothing to do with the investigation.

Keeping pace with the threat

Twenty-five years on from 9/11, terrorism is still a serious threat.

But the technology surrounding it has evolved beyond recognition.

Terrorists and extremists today have access to tools that those planning attacks in 2001 could never have imagined. They can communicate across borders instantly, distribute material to huge audiences and build online communities without ever meeting in person.

But technology works both ways.

The same advances can help law enforcement search evidence, identify known material, uncover connections and focus limited investigative resources on the information that matters.

Technology alone will never prevent terrorism or radicalisation. Human judgement, intelligence and effective intervention will always be critical.

But the front line against terrorism now begins long before an attack takes place. It begins when extremist narratives reach individuals, when important evidence is hidden among huge volumes of data and when investigators have an opportunity to identify a threat before it progresses towards violence.

We cannot stop terrorists and extremists exploiting new technology, but we can ensure those fighting them have the tools they need to keep pace with the threat.