For ethical piracy, I would say definitely if the content is no longer available through official channels.
Other situations include:
- downloading a copy of equal quality to one you already have a physical copy of, but don’t have the equipment to rip it
- really old stuff that should be public domain, but isn’t because copyright law is broken
- downloading the cracked copy of a game because DRM in your purchased copy makes it unusable
I personally avoid DRM protected digital purchases unless I can strip it out. I prefer ripping movies myself, but I don’t have any issues buying DRM-free music. I also wouldn’t mind paying for a kindle book given that I can always import it into Calibre and end up with a DRM-free copy.