1. If you, C3 team, don't want to make noise, why did you start to use a public internet site where anybody can download your stuff? That's the opposite of not making noise. I'm pretty sure you're not making noise nowadays because not many people are interested in multitracks. But, if a lot of people suddenly want multitracks, you know how internet works, C3 site would be spreaded like wildfire.
2. I don't get why labels, Harmonix or whatever can get hurt by isolated instruments, but they don't care/don't get hurt about the millions of sites that has the entire mixed copyrighted song. If it's because money, and it's always about money, I would care more about what I sell. You buy CD's, entire songs, not multitracks. So it does more hurt an entire song that only part of it, cause you can buy or download for free the entire song, but you can only download for free from internet that isolated instrument of the song (and then you are not competing with any label cause you're not sharing for free anything they are selling). To sum up, if you upload an entire song, you are competing them, but if you upload part of it or an isolated instrument, then you're not competing with anyone, cause no one here is selling multitracks in the market like that.
3. They are so available. Just search in YouTube. Almost any song I searched for using "name of the song + multitrack/stem/isolated" was uploaded to YouTube. Or even better, you google Metallica + stems/multitrack/isolated, and you get tons of sites that share plenty of them. So the point is, if anyone want a multitrack, they can get it for sure using the first page of Google.
4. Phase Shift or C3 are definitely not the first sites that somebody looking for a download link of an album would look at, but anyways, they both are dealing with copyrighted material, so there are plenty of reasons to put on the table to close both sites if any company wants to. I don't know, I see it like... it's like an assassin that has killed a lot of people tries to be less "assassin-ness" by not killing kids. I mean, the police has plenty of reasons to arrest him, it doesn't matter if the assassin doesn't kill kids no more.
5. What's really the problem about multitracks? I mean, there're people that can sell them, OK, but are they really a menace? Unless there was a site with millions of views per week that sells multitracks and people earn big bucks, someone selling multitracks does not hurt anybody, mainly because no-one will ever notice. I'm not justifying it. If I upload a Metallica album to a free share page, someone downloads it and then sells it to a guy, I wouldn't like it, but it would not hurt me in any way. And I still can hardly imagine that someone can find a guy that is all set to pay for them; cause you got to find someone "dumb" enough that did not google "Metallica multitracks" before.
What else can you do with multitracks that C3 people hate so much they had to encrypt all the stuff?

6. If copyright here is the issue, they could shut down these both sites tomorrow. Why they don't do it? Don't they know about these 2 sites? If they are still available because they are not too famous (Harmonix and co don't know about these 2 sites), then here's another paradox. You create a web site to be spreaded like wildfire, that's internet, that's the basis of internet. If you just want to share privately, then you don't open a public domain and share it to the world. You can't trust the longevity of your website on depending how famous it is. I mean, what's the logic? Let's open a web site and do not too "legal" stuff, and let's hope we don't do much noise, cause if we do, we close. Let's hope we get 4000 users per week. If we go further, they shut this down. That has no sense, right?