PORT-AU-PRINCE (Reuters) - Thousands of Haitians took to the streets in Port-au-Prince on Wednesday to express their anger against armed gangs that control nearly all of the capital and surrounding areas and the government's failure to hold them off. Violent armed groups have united behind a coalition known as Viv Ansanm and forced over 1 million people from their homes, which has contributed to a freezing of the economy and fueled mass hunger. The transitional government, a rotating body of presidential council members appointed nearly a year ago, alongside a long undermanned and underfunded U.N.-backed security mission, have done little to hold off the gangs' advances.