According to the RIAA website: "There's no legal "right" to copy the copyrighted music on a CD onto a CD-R. However, burning a copy of CD onto a CD-R, or transferring a copy onto your computer hard drive or your portable music player, won't usually raise concerns so long as the copy is made from an authorized original CD that you legitimately own and the copy is just for your personal use. It's not a personal use - in fact, it's illegal - to give away the copy or lend it to others for copying."
The reason I bring this up is I recently stumbled onto a site that copies your CDs into digital files and then offers the option of selling your CDs for you. I have a hard time believing that this doesn't violate copyright laws.
Basically, the way I interpret the current US law is that you can copy any CD you OWN, but the second you no longer own the CD, you no longer have the right to have a copy in your possession and your copies must be destroyed as they are now illegal. So, if you sell a CD, or if a third party such as this copy website, sells your CD the digital files generated by that CD are only the legitimate property of the NEW owner of the CD, which ain't you.
You might wonder why I'm not posting a link to this site. The reason is simple - I do not condone illegal copying.
So, what should you do with all those CDs that are already ripped into your computer music library, that taking up valuable space in your bookshelves?
If you are tight on space and sure that you will never again listen to the physical CD you have few legal options. The law, as interpreted by RIAA and the courts, requires that for computer use you must have possession and ownership of the CD. The simple solution is to put all your CDs into boxes and then into storage.
But if you live in an apartment in a city you may not have any additional storage space to park your fallow CDs, what then? The best solution I've come up with is the "CD cube system." It requires quite a bit of superglue, but the final result will be a set of cubes made entirely of CDs that you can stack to make into a table or a bench (with a nice cushion on top).
Stupid? You bet...but at least it's legal.