A black bloc is a tactic used by protesters who wear black clothing, ski masks, scarves, sunglasses, motorcycle helmets with padding or other face-concealing and face-protecting items. The clothing is used to conceal wearers' identities and hinder criminal prosecution by making it difficult to distinguish between participants. It is also used to protect their faces and eyes from pepper spray, which is used by police during protests or civil unrest. The tactic also allows the group to appear as one large unified mass. Black bloc participants are often associated with anarchism, anarcho-communism, communism, libertarian socialism and the anti-globalization movement. The tactic was developed in the 1980s in the European autonomist movement's protests against squatter evictions, nuclear power, and restrictions on abortion, as well as other influences. Black blocs gained broader media attention outside Europe during the 1999 Seattle WTO protests, when a black bloc damaged property of Gap, Starbucks, Old Navy, and other multinational retail locations in downtown Seattle. In February 1967, the anarchist group Black Mask marched on Wall Street in New York City wearing black clothes and balaclavas. This was the first instance of a social movement in the western world utilizing masks and black dress, which were used not for purposes of disguise but to signify a militant identity. In this regard, Black Mask anticipated and may have indirectly influenced the black bloc tactic. This tactic was developed in response to increased use of police force following the 1977 Brokdorf demonstration. On 1 May 1987, demonstrators in Berlin-Kreuzberg were confronted by West Berlin police. After this, thousands of people attacked the police with rocks, bottles and Molotov cocktails. The riots at the May Day in Kreuzberg became famous after the police had to completely pull out of the "SO 36" neighborhood in Kreuzberg for several hours, and rioters looted shops together with residents.