Understanding and countering terrorist activities poses a significant challenge to national and international law enforcement and security services. Intelligence and counter-terrorism are two of the most important tools states need to preserve their security. These activities include investigations, collection of specific intelligence data and the development of effective anticipatory strategies. However, in a democratic society, there must be several limits placed on the power of the state to protect the constitutionally guaranteed rights of citizens. The first, which is intrinsically linked to the prevention of possible crimes and terrorist actions, depends on the uncertainty as to how and when they might take place, and therefore all investigative action is essentially based on alerts from other countries, on the assessment of risks linked to particular events or geopolitical situations, on checks and interceptions, or on the infiltration of undercover agents. In other words, it is often just a matter of suspicions or scenarios and forecasts that lead to the decision to take specific anticipatory action. Great help comes from technology, which certainly increases intelligence capabilities, but collecting data and information on people who have not yet committed crimes can also be a risky process, sometimes resulting in the creation of personal dossiers that can also be used for political, defamatory or intimidating purposes. Without underestimating the information overload that accumulates in the digital archives of the various police and intelligence agencies. Anti-terrorist measures must therefore operate in compliance with national and international laws, and any overly aggressive tactics may lead to the infringement or even disrespect of individual rights, or of those communities that for religious, ethnic or political reasons are deemed more prone to radicalisation or violence. At the international level, the UN General Assembly adopted the Global Counter-Terrorism Strategy on 8 September 2006, which is reviewed every two years. The latter is a unique global instrument aimed at strengthening national, regional and international efforts against terrorism. The document clearly reaffirms that cooperation between states, coordination between intelligence agencies, between Interpol and the various national law enforcement agencies, aimed at effective prevention and suppression of international terrorism are crucial and essential, but all this must take place with full respect for human rights and democratic values.
