The Industrial Workers of the World was a Union formed in 1905 by workers, (mostly miners) who were against the exclusionary policies of the more popular, common union-American Federation of Labor. The union was founded in Chicago during a convention made up of socialists and anarchists. The union was a tight-knit union and that was their objective and agenda. The motto was “An injury to one, is an injury to all”. Its goal was to promote worker solidarity.
The picture above is the label of the Workers of the World. The picture was found on wikipedia and the link to it is http://en.wikipedia.org/wiki/File:Label.svg . As per Wikipedia, the logo was found through the the IWW website.