It's legal for me to make a backup copy of my media, in case of theft or destruction, except that owning or building the tools to allow me to create the copy is not legal -- although arguably this makes any turing machine attached to a CD/DVD/Blu-Ray drive illegal.
It's legal for me to watch tv or listen to radio for free by receiving transmissions, and I can even record them and keep the recording indefinitely as long as I only use it for personal use, but it's illegal for me to stream media over the internet and capture the stream, and it's illegal for me to transmit over the internet.
It's legal for me to trade or lend CDs, DVDs, etc. with friends I know, or to buy or sell used copies, as long as they're legitimate (not pirated), but it's illegal for me to use the internet to facilitate either the search or the trading or to expand my group of "friends", even though I could go to a public library and essentially achieve the same ends by swapping media with a large group of people (the public) who I don't actually know.
If something is out of print, or censored, or otherwise unavailable, but copyrighted, I have no legal recourse to obtain a copy.