Cory Doctorow adds: "DRM is like the Ford Pinto: it's a smooth ride, right up the point at which it explodes and ruins your day.
I mean it. When HarperCollins backs down and says, "Oh, no, sorry, we didn't mean it, you can have unlimited ebook checkouts," the libraries' answers should be "Not good enough. We want DRM-free or nothing." Stop buying DRM ebooks. Do you think that if you buy twice, or three times, or ten times as many crippled books that you'll get more negotiating leverage with which to overcome abusive crap like this? Do you think that if more of your patrons come to rely on you for ebooks for their devices, that DRM vendors won't notice that your relevance is tied to their product and tighten the screws?
You have exactly one weapon in your arsenal to keep yourself from being caught in this leg-hold trap: your collections budget. Stop buying from publishers who stick time-bombs in their ebooks. Yes, you can go to the Copyright Office every three years and ask for a temporary exemption to the DMCA to let your jailbreak your collections, but that isn't Plan B, it's Plan Z. Plan A is to stop putting dangerous, anti-patron technology into your collections in the first place. "