Originally Posted by HarryT
Format conversion is a rather "grey area" of copyright law. It's not at all clear in many countries that it falls into the category of "fair use". In the UK, for example, it is specifically NOT legal to "rip" CDs that you've bought (I'm not saying that people don't do it, just that it's not legal). I believe that it may perhaps be legal in the US.
Yes, in the US it's considered "fair use" to rip CDs. However, US law is vague on what "fair use" actually means, so you can still get in trouble depending on exactly what you do with those ripped files.