Wild cat (some say it's a lynx) is a symbol of wild strikes that were organised by workers in XIX century.
Brilliant image. came across a story that explains why the black cat is associated with socialists and anarchists. This story was in a copy of WSM(workers solidarity movement)an Irish anarchist magazine, the symbol originated with the I.W.W. The International Workers of the World a syndicalist group which had lots or anarchist members.
They were involved in organising trade unions across U.S.A at a time Coal mine owners and industrialists were not above hiring armed thugs to break union strikes, at one such strike organised by the I.W.W. a mangy black cat turned up as the strike turned vicious with strike breakers, some of the workers took to feeding the cat after which the workers won their demands. Because of that the union members considered the cat their lucky mascot and adopted it as their symbol.