At Comics Worth Reading, Johanna Draper Carlson makes the argument that it is ethical to download "pirate" comics if you have already bought the hard copy, but you want a digital copy for the sake of convenience.
My husband, an old-school comic fan, is a fanatic for keeping the periodical comics in near-perfect shape. Me, I’m not quite so careful with them (since for me, they’re to be read and probably forgotten before the next chapter comes out). My graphic novels are sturdier and hold up better to sloppy handling. So to keep the peace, and avoid having an unhappy husband, I’m contemplating downloading versions of the comics we have already bought. That way, KC has the paper objects, and I have versions to read without worrying about what condition they’re in or if I’m stacking them too high or piling things on top of them. Plus, I can take comic books with me while traveling, something I’d otherwise never do with individual issues. (I read them too quickly to justify the space in packing them.)
This argument has the endorsement of Randy Cohen, the Ethicist columnist for the New York Times, who wrote:
Buying a book or a piece of music should be regarded as a license to enjoy it on any platform. Sadly, the anachronistic conventions of bookselling and copyright law lag the technology. Thus you’ve violated the publishing company’s legal right to control the distribution of its intellectual property, but you’ve done no harm or so little as to meet my threshold of acceptability.
But is that really so? Suppose I paid top dollar for a hardback novel, and then I wanted a paperback to read on the subway. Am I entitled to walk into a bookstore, pick up a paperback, and walk out without paying? Both ethics and the law say no.
Furthermore, while Carlson and Cohen don't seem to think anyone is being deprived of income by scanning or downloading comics you already own, I'm inclined to disagree. If the comic is available digitally, then yes, you are depriving them of income. My own solution, for a comic I don't want to keep, would be to buy it digitally in the first place.