Anyone can throw up a web page and say that their product is legal.
I believe that to be legal they would have to be playing the songs back through WMP or iTunes and then hijacking the audio stream to get the audio, not playing back and re-encoding the file directly. But I'm no expert. I just doubts that Apple or Microsoft are likely say "Yep, they're both fine".
With iTunes you don't need to strip the DRM to backup your music. Not sure about WMA but I'm sure it must have some backup provision in their too. In fact IIRC there is an option under WMP to backup licences.
Anyway - if you just want to strip DRM I'm sure they work, but I have no direct experience with either.
