Caveat: I'm not a big fan of format shifting. Copyright law effectively gives publishers the right to determine not only the number of copies, but the format in which those copies are created. A classical example is hardback vs. soft cover books. A hardback book may have additional value because it has a better quality binding, better quality paper, and a more durable cover. Some books may also offer colour illustrations and other value added features. Should someone be able to buy a soft cover book then reprint a hard cover edition from it? I know that sounds silly, but that's only because of the economics of the situation. A publisher could easily argue that a digital copy adds extra value because it is indestructible, is incredibly portable, adds conveniences such as keyword search, and features such as colour illustrations. (I don't necessarily agree with that assessment, but they probably would. And they are the ones who matter here!) In this situation the possibility of format shifting doesn't sound so silly because the economics work out, which is why many people think that it is okay.

That being said, I do believe that anti-circumvention tools should be legal. But that is to protect rights that I view as more fundamental. I believe in the doctrine of first sale and that consumers have the right to circumvent vendor lock-in (e.g. being tied to particular vendor's ereader). Yet I think that you should be the one who is using the tools, rather than letting the pirates do it for you. After all, the simple act of visiting a pirate website (never mind downloading a copy) is supporting illegal activities.