The colors black and red have been used by anarchists since at least the late 1800s, though generally used by anarcho-communists. The flag was used as the symbol of the anarcho-syndicalists by the CNT during the Spanish Civil War. The black represents anarchism and the red represents leftist and socialist ideals. George Woodcock writes that the bisected black-and-red flag symbolized a uniting of "the spirit of later anarchism with the mass appeal of the First International"
A.C.A.B. (All Cops Are Bastards) is an acronym used as a political slogan associated with radical activists who are opposed to the police. It is typically written as a catchphrase in graffiti, tattoos, or other imagery in public spaces. It is sometimes numerically rendered as "1312," representing the ordering of the letters in the alphabet. During the 1980s, ACAB became a symbol of anti-Establishment, especially within the punk and skinhead subcultures. It was popularized in particular by the 1982 song "A.C.A.B." by Oi! band The 4-Skins. In later years, ACAB turned into a popular slogan among European football hooligans and ultras, and among anarchist and anti-authoritarian movements
… Read more across the world. In the wake of the May 2020 murder of George Floyd by police officer Derek Chauvin, the use of the term A.C.A.B. became more frequently used by those who oppose police brutality. As protests in response to Floyd's death and discussions about racially motivated police violence spread through the United States, A.C.A.B. was more frequently referenced on social media