This is what I found on the RIAA’s website:
*Copying CDs
It’s okay to copy music onto an analog cassette, but not for commercial purposes.
It’s also okay to copy music onto special Audio CD-R’s, mini-discs, and digital tapes (because royalties have been paid on them) – but, again, not for commercial purposes.
**Beyond that, 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
—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 owners of copyrighted music have the right to use protection technology to allow or prevent copying.
Remember, it’s never okay to sell or make commercial use of a copy that you make.
(From the RIAA: Piracy: Online and On The Street: The Law, under the heading “Copying CDs”
riaa.com/physicalpiracy.php?content_selector=piracy_online_the_law)
Now note the bolded section; it says that there is no “legal right” to copy CDs for personal use and that transfering music to, say, a portable music player “won’t usually raise concerns” as long as we follow those guidelines. Would it still be morally acceptable to transfer music, then, onto a flash drive and onto a cell phone for personal listening and use?