The 4F case concerns the events of 4 February 2006 in Barcelona, in which a policeman patrolling outside a rave was paralyzed after being hit by a falling object and nine people were arrested in consequence. At a trial two years later, seven people were convicted, one of whom was then pardoned. On appeal to the Supreme Court, the sentences were lengthened and one person committed suicide.
The 4F case caused controversy and resulted in a film, Ciutat Morta, which argued that those convicted were not responsible for the policeman's injury. The film was viewed over 500,000 times when screened on Catalan television, which then created a further debate both about the case and more general issues such as police violence and gentrification in Barcelona. New mayor Ada Colau pledged to reform the Guàrdia Urbana and an investigation decided not to overturn the convictions.