Well that comes under the heading of which copyright law and where...... Here in the UK, for example, I don't think it's strictly legal to create a backup copy of installation medium or original music CDs anymore (though everyone knows that pretty much everyone copies their CDs to iTunes (or equivalent) and then copies onto iPod (or equivalent) these days. And for anything protected by encryption, we now have legal provisions similar to DMCA (i.e. it is illegal to try and circumvent a copy protection mechanism, regardless of how poor that mechanism is).

One of the reasons I still have a soft spot for the CD is that there's no copy protection and therefore no technical limits on how I, as a consumer can use the content.