Someone has created a terrifying Metallica/Megadeth/Rihanna mashup

First Lady Gaga performs with Metallica at the Grammys, now some joker's decided it was a good idea to mix 'em up with Megadeth (sensitive topic, but we'll allow it) and Rihanna (wait, what?).

There's also video footage of Gorillaz, GNR and *shudder* Miley Cyrus. What kind of sin is this?