BRUSSELS — Twenty-five years after the September 11 attacks transformed the global fight against terrorism, European security officials are warning that the threat is changing in a significant way. While jihadist organizations remain a major concern, authorities are increasingly focused on loosely organized online communities that can encourage young people to commit violence without a clear political or religious ideology.
European Union Counter-Terrorism Coordinator Bartjan Wegter says the emerging phenomenon, described as nihilistic violent extremism, is largely driven by fascination with violence, online recognition and status rather than traditional extremist beliefs.
Investigators from nine European countries identified roughly 4,340 web addresses associated with an online community known as “The COM” during disruption operations conducted in June and July.
Youth-Driven Extremism Moves From Online Communities to Real-World Violence
European officials say some online groups are increasingly connecting young people with violent material and encouraging acts that can move from digital spaces into the real world.
The phenomenon has become particularly difficult for authorities to detect because many suspected perpetrators are young, have no previous criminal record and may leave little evidence outside encrypted online communities.
In 2025, a 16-year-old in Finland was accused of stabbing three female students. Authorities said he had shared a manifesto through messaging groups and recorded the attack, while investigators found no clear political motivation behind the incident.
A separate case in Italy involved a 15-year-old accused of planning a killing in an effort to gain online notoriety. Authorities said his phone contained extensive violent material.
Officials believe similar incidents have increased over the past two to three years, raising concerns that online communities can turn violent acts into a form of entertainment or social currency.
Terrorism Threat Remains, With Jihadist Networks Still Responsible for Major Share
The rise of nihilistic extremism does not mean Europe’s traditional terrorism threats have disappeared.
According to European data, 45 terrorist attacks were reported across 10 EU countries last year. Although none developed into major mass-casualty attacks, six people were killed. Authorities also arrested 486 people suspected of terrorism-related activities across 21 EU member states.
Jihadist groups were linked to 24 of the reported attacks and accounted for more than 70% of the arrests. Around one-third of those arrested were under 18, with boys making up most of that group.
Authorities are also monitoring networks such as 764, an online community associated with severe criminal and violent activity. European officials say such networks demonstrate how extremist communities can operate across borders without relying on the centralized structures that characterized some terrorist organizations in previous decades.
The shift has made the digital environment an increasingly important battleground for European law enforcement.
AI Adds a New Dimension to Online Extremism
Artificial intelligence is creating another challenge for investigators. European authorities say criminals and extremists are using AI-related tools to produce and distribute propaganda, manipulate images and audio, and expand the reach of extremist material.
Deepfakes, memes, GIFs and automated accounts can make violent or extremist content easier to produce and circulate. Authorities also warn that AI-powered systems can be exploited to support recruitment and research related to attacks.
EU officials say around 85% of investigations now involve a digital component, highlighting how heavily modern criminal and extremist activity depends on online technology.
The growing threat is creating a difficult balance between public safety and privacy. Security agencies argue that investigators need modern digital tools to respond effectively, while privacy advocates warn against excessive surveillance and unjustified intrusion.
As Europe approaches the 25th anniversary of 9/11, officials say the terrorism landscape is increasingly fragmented, decentralized and digitally driven. The challenge is no longer only identifying established extremist organizations — it is also detecting young people who may become involved in violent online communities before digital fascination turns into real-world attacks.
