Many of the teenagers who have the image on their shirts, bags or whatever, probably just think of it as a cool picture, and don't think too much about the meaning. I'm saying many, not all, or even most. I suppose the majority of people are aware of who Che Guevara was, and what his background was, and could at the very least say "socialist rebel from Cuba". The famous picture alone is so strong in its expression of rebellion that you don't need to identify with Communism or Socialism to feel drawn to it. It expresses steadfast determination and unbreakable spirit in the face of a young, rugged, unshaved man, looking towards a golden future he is ready to give his life for. Regardless of the political background, I find it very difficult not to be captivated by the sheer power of the image.