Halloween under surveillance in Madrid and Barcelona: what the Police is preparing in response to the threats from Blocus

The investigation into the incidents associated with Blocus in Barcelona remains open and in an initial phase, according to information available as of October 28, 2026. The known actions refer to the riots and looting on October 24: precautionary measures have already been taken against detainees, while the identification of those who disseminated or coordinated the calls continues. Criminal liability of Blocus as an organization has not yet been established.

Status of the detainees

The initial count was 128 detainees, including 72 minors, according to Demócrata. This figure corresponds to police arrests, not convictions or persons who remain deprived of liberty. The Barcelona City Council also confirmed the opening of an investigation into those responsible for the calls, parallel to actions against those who physically participated in the events.

• Adults: most have been released provisionally, with periodic appearances and, in certain cases, prohibition from attending demonstrations. Two suspects face charges for public disorder related to throwing stones, cobblestones, and other objects at officers, according to information from Infobae and ARA.
• Minors: three were placed in closed custody; others were subject to supervised release or other measures, including prohibition from participating in gatherings. El Periódico reports these actions. It is important to distinguish the detention request made by the Prosecutor's Office from the measures ultimately agreed upon.

What is being investigated about Blocus

The second line of work seeks to identify the administrators of accounts and groups used for the calls. According to RTVE, the Mossos are studying how to track these channels and plan to request judicial authorization to access data such as IP addresses and communications. The available information does not allow presenting these authorizations as already granted.

Investigators analyze images, messages, connections between accounts, and possible instructions to attack businesses or confront the police. They also try to identify more participants in the looting and determine if there was organized coordination, as explained by El Nacional. The path from TikTok to Telegram and WhatsApp groups is relevant because open posts did not necessarily show all the instructions shared afterward.

What has not yet been established

Sharing the name Blocus does not prove a single leadership. Demócrata points out that it is still necessary to establish who used the accounts, how they related, and what responsibility corresponds to each message or action. An international structure has not been established either, although there are contacts with other European police forces to examine possible connections.

The legal information collected by laSexta distinguishes between administering a group or calling a protest and possible criminal liability: this would require proving a specific incitement to commit a crime or participation in the acts. Therefore, a police hypothesis should not be confused with a judicial conclusion.

The Generalitat has announced it will appear as a private prosecution and the City Council has also announced legal actions for damages. In summary, there are individual actions and precautionary measures, but clarifying coordination and attributing responsibilities remains pending. The consulted sources do not record a sentence or the closure of the investigation.

In Catalonia, the Mossos d’Esquadra are the body responsible, in general, for maintaining and restoring public order, including urban disturbances. The National Police retains its state competencies and may intervene to exercise them or provide support, but it does not automatically replace the Mossos due to the severity of incidents.

The division is mainly based on the Constitution, Article 164 of the Statute of Autonomy of Catalonia, and Organic Law 2/1986, on Security Forces and Corps. Police action must also respect regulations on citizen security and the right of assembly.

Competencies of the Mossos d’Esquadra

Within Catalonia’s territory, they are responsible for the ordinary response to citizen security and public order. In an episode of disturbances, this includes:

• Prevention and assessment: evaluating risks, deploying surveillance, and preparing devices ahead of gatherings or situations that may lead to violence.
• Protection: safeguarding the security of participants, neighbors, and third parties, as well as protecting property and public spaces.
• Restoration of order: intervening against assaults, damages, and other disruptions, using appropriate units and means.
• Criminal action: arresting alleged perpetrators and investigating crimes committed, within their competencies as judicial police.
• Local coordination: organizing collaboration with local police to address the incident’s effects on the municipality.

In demonstrations, their role is not only to control incidents: they must also protect the peaceful exercise of the right of assembly. A gathering alone does not justify coercive intervention.

Competencies of the National Police

The National Police maintains presence and powers in Catalonia. Among its state functions are documentation, immigration, and control of entry and exit from the territory, as well as protection and investigation actions legally assigned to it.

Regarding urban disturbances, its intervention may occur mainly in these cases:

• Own state competence: for example, protection of state dependencies whose security it is entrusted with. This intervention does not imply assuming all public order of nearby streets.
• Support to the Mossos: when requested or agreed upon through legal collaboration mechanisms.
• Joint operations: when autonomous and state responsibilities coincide, with distribution of zones, objectives, and tasks.
• Situations of state scope: when there is a specific legal authorization for reinforced coordination or command.

Therefore, the severity of the disturbance alone is not enough to displace the Mossos. Nor does autonomous competence prevent the National Police from legitimately acting in its own matters.

Coordination and command

The Security Board of Catalonia is the main bilateral coordination body. Specific operations are articulated through plans, protocols, information exchange, and operational centers, delimiting each body’s responsibilities.

In major events, autonomous responsibility over citizen security and public order may coexist with state missions of protection. The ordinary direction of the autonomous operation should not be confused with command of all participating forces: the specific scheme must be defined in operational coordination.

Common limits of intervention

Both bodies must act according to the principles of consistency, opportunity, and proportionality, respecting fundamental rights. The use of coercive means must respond to circumstances and existing risk, not simply to the presence of a protest.

In summary: the Mossos ordinarily manage urban disturbances in Catalonia; the National Police exercises its state competencies and collaborates when appropriate. Exceptional direction requires a concrete legal basis, not a generic invocation of public security.

In Spain, a call is not illegal simply because it is controversial, annoying, or contrary to an authority’s position. To consider it unlawful, an applicable obligation or prohibition must be identified and the facts that violate it justified. Additionally, three issues must be distinguished: a formal defect, a possible prohibition of the act, and the commission of a crime.

As a "call" can refer to a demonstration, a strike, elections, or a corporate meeting, there is no single answer for all these cases. The following explanation focuses on citizen meetings and demonstrations, with a final clarification on strikes.

1. Identify the applicable right and norm

The framework for meetings and demonstrations is found in Article 21 of the Constitution and Organic Law 9/1983, regulating the right of assembly. Its application must respect one premise: these are basic political freedoms and their limitations must be interpreted restrictively, as recalled by the Constitutional Court Ruling 133/2021.

Therefore, it is not enough to publicly label a call as "illegal." It must be specified whether its purpose, organization method, compliance with communication obligations, or behaviors during its celebration are questioned.

2. Differentiate formal breaches and material limits

Lack of prior communication does not, by itself, constitute a crime. Jurisprudence distinguishes the exercise of the right of assembly from failure to notify certain gatherings or demonstrations. Ruling 172/2020 addresses precisely this separation.

There are also organizational obligations. Ruling 61/2023 reminds that organizers must adopt measures for the proper development of the meeting and that the communication must include the security measures planned or requested from the authority.

These requirements must be analyzed separately from the material limits of the right: a documentary irregularity and violent conduct are not legally the same nor do they automatically allow attributing identical responsibility.

3. Justify prohibition or intervention

The decision to prevent a meeting requires relating the facts to the applicable constitutional limits. It cannot rest solely on disagreements with the message of those calling it.

The examination does not end when the act begins either. Ruling 42/2000 explains that violations of those limits may occur during its development. Therefore, circumstances known before the call, subsequent behaviors, and the specific actions of each participant must be distinguished.

4. Do not confuse administrative and criminal liability

To affirm that a crime exists, conduct fitting a Penal Code figure must be identified and its elements proven. Threats, coercion, injuries, damages, or public disorder require their own analysis; they cannot be deduced simply from attending a protest.

Likewise, it must be explained to whom the acts are attributed and why: caller, organizer, or participant. Individual responsibility should not be replaced by a generic imputation to all attendees.

5. If it is a strike

The call requires a different analysis, according to strike right regulation. Not every administrative restriction is valid either: Ruling 2/2022 examines the proportionality of minimum services and their effect on the effective exercise of the right.

In summary: the type of call, the breached norm, the proven facts, the responsible persons, and the corresponding legal consequence must be specified. Without this distinction, calling a call "illegal" does not constitute sufficient legal justification.