It was a peer-to-peer network. Would they sue every single person for sharing with every other person, over and over again? (E.g. if there are 10 nodes, would every one be sued for sharing 9 copies?) That doesn't make much sense.
Also, if your peer to peer network has you downloading the same thing over and over again, then your peer-to-peer network is broken.
Historically, I don't think this would come up as much in copyright law. General torts often involve a confluence of events triggered by multiple actors, whereas copyright violations have usually been clearly the act of a single person or entity, so I'm not sure there's much case law around this.
Mostly true, but I feel like I must point out that fair use (what narrow legally defined version of it we have, anyways) overrides the copyright owner's wishes.
Not that this applied here, but it's an important point anyways.
I guess you could argue that if 5 people worked together to steal a car, they all get charged with attempted theft of that car. In other words 1 person doesn't get charged and 4 get to go free, or they don't all get charged with attempted theft of 1/5 of a car.
I would think though that could be an argument against the supposed lost revenue. I'm sure the content companies are doing the math to show the highest figures possible.
Using the car example, the car owner shouldn't be awarded 4x the value of the car just because 4 people were involved.
Also, it's still copyright infringement to provide a copy to someone even if they already have it. I cannot, legally, provide a rip of a CD to anyone who has a cassette tape of the same album.
I don't think it's clear either way.
One famous case is this one: http://en.wikipedia.org/wiki/L.A._Times_v._Free_Republic
The judge held that "while defendants' do not necessarily 'exploit' the articles for commercial gain, their posting to the Free Republic site allows defendants and other visitors to avoid paying the 'customary price' charged for the works".
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes; (2) the nature of the copyrighted work; (3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and (4) the effect of the use upon the potential market for or value of the copyrighted work.
https://w2.eff.org/IP/eff_fair_use_faq.php
Although the legal basis is not completely settled, many lawyers believe that the following (and many other uses) are also fair uses:
Space-shifting or format-shifting - that is, taking content you own in one format and putting it into another format, for personal, non-commercial use. For instance, "ripping" an audio CD (that is, making an MP3-format version of an audio CD that you already own) is considered fair use by many lawyers, based on the 1984 Betamax decision and the 1999 Rio MP3 player decision (RIAA v. Diamond Multimedia, 180 F. 3d 1072, 1079, 9th Circ. 1999.)
Making a personal back-up copy of content you own - for instance, burning a copy of an audio CD you own.
Yes you can backup or transfer your copy to other formats or media. But you cannot redistribute that copy to others, even if those people have a license for it.
And yes, archival and format-shifting is possible because of fair use clauses, but those clauses do not extend to redistribution of the work as a whole, even if done for noble purposes and in the public interest.
And even in cases where you could redistribute parts of the work, with the purpose of criticism or parody, the end result and intent matter a lot when judging if fair use clauses apply or not.