I got into this debate with a friend serveral years ago over a couple of lunch time cocktails. She thought that sharing of music files ala Napster, et al was perfectly okay. Her point was that she could loan me a CD that I hadn't paid for. I countered with yeah well I could also go to the library and check out virtually any Jazz artist's CD that I wanted and rip that for my continued listenting pleasure but the real difference is when you look around this restaurant and walk up to anyone and swap CD's with people you do not know then there's real and tangible loss in it for the music makers and the record labels that produce them. Multiply that ability to extend to virtually anywhere in the world where the internet has reach and it's fairly easy to see that the labels and musicians stand to lose countless amounts of money through copyright infringement.
I don't agree with Media Defender's tactics but on the other hand I don't agree with free file sharing. Media Defender's approach seems to border on entrapment ala the methods used by vice to catch would be solicitors which isn't exactly ethical.
The bottom line for me personally is that I don't engage in that behavior so I don't anticiapte ever running into Media Defender (or Vice -- just to be clear!
). I can't tell you the number of times I have avoided bad behavior and never been hassled by authorities...