"Making a profit off of public domain works is allowed; indeed, it’s half the point. You’re allowed to make a hip-hop rendition of Shakespeare’s sonnets and then sell it to make money. The crux of the matter here is balancing the public interest against private interests; individuals should have the right to be compensated for their work, and the public should be free to reuse and remix the products of our shared culture."
Maria Bustillos on public domain, copyright law and the infamous Aaron Swartz / JSTOR case