Odhanan said:
For me, it's not a question of justification for file sharing or not.
File sharing of copyrighted material in the US is illegal. Period.
You don't like it? Vote for a guy who would change the law then, or better yet, run for Congress, or expatriate yourself in a country where this is legal. Until you do that, it is criminal under the rules of the US society. What's so hard to understand?
Bzzt! Wrong!
I have here a set of all the PDF works I have published. I own the copyright on them. It is legal for me to make them available via a filesharing network.
I have also a copy of the SRD, complete with OGL... and a copy of the latest Linux distro, complete with GPL. Because I have explicit permission from the copyright holders (through the licenses) to distribute them, it is legal for me to make them available via filesharing.
In both of these cases, I am file sharing copyrighted material in the US. And in both cases, it is 100% legal. Period.
The existence of filesharing itself is NOT the cause of the problem of copyright infringement, any more than the existence of cars is the cause of traffic law violations. To wit, filesharing is a tool (not the only one, think of "usenet" or "sneakernet") which allows human actors to violate laws, not the violator of laws itself.
I don't think the actual legality of sharing PDFs (without the permission of the copyright holder) on a filesharing network in the US has been questioned here, so I'm confused as to what point you're trying to make. There have been some arguments as to whether or not this is ETHICAL, but "ethical" and "legal" are not always the same (in US law alone, we can cite slavery, Jim Crow laws, separate but equal, women's suffrage, Persons with Disabilities Act, etc. etc. etc.).
Despite your flawed premise, you did make a good point at the end - if you don't like the law, the U.S. system gives you the opportunity to change it. So yes, if you're in the US, and you don't like it, start trying to take advantage of the system and get the change you're looking for.
--The Sigil