Are+biofuels+sustainable?

Are biofueld sustainable? (or, more focused: Should investment in food-based biofuels be extended?)

Wynne, Wright, and Taylor Reid. "Green dreams or pipe dreams?: Media framing of the U.S. biofuels movement." Biomass and Bioenergy. (2010): 1-10. Print. (Alicia Lin's annotation: http://sustainabilitypathways.wikispaces.com/Annotation_14)

Also see: http://oilpoliticsrpi.wikispaces.com/articles+on+biofuels