I read this ages ago, but I recall it touching on owners of virtual pets forming groups to try to keep their pets and the environments they live in going after the company that originally created them all folds. Well, I just came across a real-life example of something similar, although from the sounds of things there won't be a happy ending. Details under a spoiler tag, because it's depressing:
Virtual pets that eat DRM-protected food, and a legal battle means their food supply is about to go poof. I've seen people talk about patching the pets so they don't need food, but it sounds like that might not be possible. :-(
ETA: The company did at least release items that could make it so the pets don't need food, although it also sterilized them. Better than falling asleep and never waking up, I guess? There's an article here.
Another thing to add to the "reasons why DRM sucks" list.