Anonymous recruitment, youth grievances and competing political narratives converge around a new form of mobilisation ahead of Spain’s November 29 election.

On October 24, violent disturbances in Barcelona left more than 30 businesses looted or damaged and 133 people arrested, 89 of them minors. Under the name Blocus (French for “blockade”), anonymous social-media accounts subsequently promoted Halloween gatherings across Spain. Comparable violence did not recur on October 31, amid arrests, communication-channel closures and extensive police deployments.

Investigations have since expanded. On November 5, Spain’s National Police reported arrests of 18 people, including 13 minors, across seven cities in an operation focused primarily on calls for disturbances around Halloween. Further calls have been identified for November 30, the day after Spain’s general election, which was brought forward following Parliament’s rejection of housing measures amid a crisis that has fuelled youth dissatisfaction.

Blocus therefore warrants examination at the intersection of social grievances, violent mobilisation and electoral politics.

From French student protests to a transferable model

In France, blocus was already used to describe student blockades of schools, rather than as the name of a particular organisation.. Protests beginning in September over educational and economic grievances sometimes escalated into violent confrontations.

Spanish accounts adopted the name and imagery, but not an identifiable common ideology. Their messages ranged from education and immigration to corruption, opposition to the Sánchez government and explicit encouragement of looting. This diversity complicates attempts to associate Blocus with any particular ideological movement.

Spanish social-media accounts presenting themselves as Blocus encouraged participants to wear black and conceal their faces, resembling the Black Bloc repertoire traditionally associated with anarchist and antifascist movements. Similar attire was also documented during the French disturbances. Although French intelligence identified some far-left involvement, no direct Antifa direction or affiliation in either country has been established.

What appears transferable from France to Spain is a mobilisation model rather than a common ideology. A Guardia Civil investigation in Tenerife identified methods inspired by French disturbances, without establishing operational direction from abroad.

How Blocus mobilised young people in Spain

Anonymous TikTok accounts and AI-generated posters presented gatherings as student protests, directing young people into private WhatsApp and Telegram groups. Invitations circulated through school chats, while private discussions included looting and attacks on businesses.

Joint investigations by the Mossos d’Esquadra (Catalan regional police) and the Spanish National Police have identified suspected organisers behind this apparently decentralised mobilisation. By November 4, seven people had been arrested in Catalonia for allegedly organising the October 24 disturbances. They included two girls aged 14 and 17, suspected of administering WhatsApp groups promoted through TikTok posters containing QR codes, and an 18-year-old woman. Two adult suspects were remanded in custody, while a 17-year-old alleged coordinator was placed in closed juvenile detention. These measures do not constitute convictions.

Separately, digital forensic evidence allegedly linked a suspected promoter detained in Valencia to several Barcelona channels, AI-generated recruitment material and a video in which a masked individual claimed to lead Blocus. The National Police also identified channels used to transmit instructions and identify targets, some of which allegedly encouraged weapons use or circulated information about incendiary devices.

These findings strengthen the evidence of coordination within particular networks, although a unified national hierarchy has not been established.

Police intervention also disrupted subsequent mobilisation. The Mossos d’Esquadra requested Telegram takedowns through CITCO, Spain’s Intelligence Center against Terrorism and Organized Crime, with four Barcelona channels closed by October 30. Madrid experienced no significant Halloween disturbances, while Bilbao's advertised gathering attracted no participants. On November 3, the Catalan government announced that it would examine whether digital platforms had fulfilled their legal obligations in relation to Blocus. TikTok and WhatsApp, alongside Telegram, featured in the mobilisation, although no particular provider had been publicly identified as having breached the law.

Political grievances and partisan attribution

Blocus’s ideological ambiguity has not prevented competing political accusations. Far right-wing part Vox suggested that Prime Minister Pedro Sánchez could have ordered the disturbances to prevent political change, while some left-wing politicians raised the possibility of far-right involvement intended to discredit legitimate housing protests. The Popular Party (PP) blamed far-left groups for the separate October 26 disturbances in Bilbao, following protests against far-right commentator Vito Quiles, and accused the government of failing to prevent the violence. No organisational connection between those Bilbao incidents and Blocus has been established.

Meanwhile, calls for gatherings on November 30 circulated across twelve Spanish cities.  Whether these calls will result in actual gatherings remains uncertain; the date alone does not establish electoral coordination.

For young voters who feel politically unrepresented, grievances may help explain the resonance of Blocus's political messaging and create conditions in which unlawful or potentially violent forms of mobilisation become more appealing.

When street violence becomes spectacle

The predominance of minors among those arrested raises another question: what attracted them? A November 1 investigation described adolescents motivated by opportunities to steal, following friends or curiosity. One explained: “Me llegó un reel y fui por curiosidad” (“I came across a reel and went out of curiosity”). A lawyer interviewed about the detained minors compared some participants’ behaviour to being inside a video game.

These explanations invite consideration of the gamification of violent extremism, although there is no evidence that Blocus employed formal gaming mechanisms. Elsewhere in Europe, Halloween calls invoked The Purge, a film whose plot revolves around a fictional night when crime is legal, while videos displayed allegedly looted goods. Such imagery may make disorder appear entertaining independently of political conviction. Research on repeated exposure to violent imagery suggests possible desensitisation among some adolescents, without establishing a causal connection to violence.

In Spain, Blocus combined genuine social grievances with suspected organised incitement, predominantly adolescent participants and competing attempts to assign the violence an ideological identity. The phenomenon illustrates how the mechanisms that attract people to collective violence may differ substantially from the objectives of those organising it, and how political actors can subsequently exploit that ambiguity.

As Spain approaches the November 29 election, distinguishing between these processes will be essential to understanding both the risks Blocus poses and the conditions that make such mobilisation possible.