[dwild]

> Why does it matter, to Metallica, where the streams are stitched together? Why does it matter, to them, that everyone watches the completely free stream of their music from a specific source, and not any other source?

A likely explanation is that they charge Blizzard based on the amount of viewers that was there.

There could also be some kind of agreement that they had control over the redistribution afterward, in case they would prefer to take it down. Once redistributed by someone external, that's no longer possible.