ob. discl. I am not a lawyer.
AIUI, copying a song off the radio onto a cassette tape is considered fair use, especially since there's a blank media tax imposed on the sale of audio cassettes intended for music --- this is also why CD-Rs which are marketed for music are more expensive, they have a ``private copying levy'' tax built into the price.
http://www4.law.cornell.edu/uscode/17/1004.html
MP3 players (and presumably ebook readers) are considered computer peripherals, so don't have such pricing regulation built into them.
Rather than seeing everyone presumed guilty and fined in advance, I'd liefer people behaved honestly and only licensed things properly --- boycott authors / companies whose DRM policies you don't agree with.
William