who is WMG?

man, this sucks, i was trying to watch my favorite videos, so when i booked marked them on youtube and then all of the sudden i get this:

This video is no longer available due to a copyright claim by WMG

so i wanted to know who in the hell is WMG stands for Warner Music Group - this is the same company that make movies like batman

well, you can bet im not buying anything from those guys. i hate when these companies do that, i mean, im not stealing anything by just watching.