The fist of solidarity. No letters here, just a clenched hand as a measure of intent. Wikipedia tells us it dates from ancient Assyria as 'a symbol of resistance in the face of violence'. It was adopted by the IWW, the Industrial Workers of the World, in 1917. It was the Republican salute in the Spanish Civil War in 1936-39, and the salute of Smith and Carlos at the 1968 Olympics during the Civil Rights Movement in the USA. It has become a symbol for human rights.
All of these symbols originate as demonstrations against violence. The fist works two ways: one as a punching fist, the other as a stilled hand: closed, the opposite of the open hand of the nazi salute. It is almost as if there is an implicit threat in the fist which can be a weapon but which actually comes from numbers, rather than any threat of individual action.
All the symbols this week have been against violence at the state level: civil and human rights, disenfranchisement, discriminatory policies. And while not all are ancient symbols, none of them are new; they aren't brands thought up by a marketting agency. Somehow these symbols carry a great dignity with them; their original intentions are so powerful that their message bypasses the intellect. I do wonder if this bypass of the intellect is not at the root of power, and can be used for both good and ill.
Below is a stencilled version of the sign for Autonomism, which is allied with socialism, marxism and anarchism, influenced by the Situationists and has a number of autonomist wings in several European countries. As the word suggests, it favours autonomous action against the structures and processes of capitalism, rather than an sort of organised mass movement. It appears to be more guerilla-like, under the radar, with activities such as absenteeism. But they have a sign.