Copyright infringement is a matter of permission. I'm not sure that it's even possible, a priori, to say that certain material is infringing, unless you have personal knowledge of who uploaded it and who is authorized to. You can usually make a good guess; but it's just a guess.

This even more complicated thanks to the fact that the record labels have authorized marketing agents to release "unauthorized" releases, even ones marked as leaks, via independent channels. They've even have had to un-DMCA them when their own legal departments took them down.

Proof of that statement can be found in the court filings for the Viacom v. YouTube case, incidentally. Lest you think that this was just the assertion of YouTube's lawyers, I will point you further to the fact that Viacom's own lawyers were forced to agree to remove their claims of infringement after it was proven that Viacom itself had uploaded those particular files.

And that? That happened twice. That's after Viacom's own expensive lawyers (allegedly) performed due diligence.

In short, I would like to point out that while you can have a pretty good idea what content is and is not authorized, there are many good reasons, based on actual events, that could give a person a reasonable doubt about whether something might be authorized, especially if there's no DMCA complaint. I can give you a long list incidents if you like, just from memory.

My point is that even the rights holder might not know if they've authorized it, and they're the only people who can be expected to know who all they've authorized.