You can have access to the internet for free, you can find content for free, but access to property you don't own for free is not the pervue of the internet.
The internet is a medium for distribution of information. Whether it be printed, or multimedia.
However, it's all copyrighted. Just because you see an image on a web page, doesn't mean you can (legally) download it and place it on your own site. Someone else created that image and owns it (and can control its use).
The same goes for music. Someone illegally copying a CD to the internet does not make it free. Rights are rights. Whether the label or the artist owns the music is irrelevant. The point is that the people who upload these MP3s do not and everyone downloading them are stealing.
Trying to argue from any other stance is sophistry or another (unrelated) argument.