I commented on a music vid and a person said "f$$$ off I just hate society I don't listen to their s$$$$ music". Now, I know it sounds obvious but is this person mad at me?

Don't worry about what they think. Be yourself. Ignore all the negative people, and embrace the positivity. If everybody dwelled on what other people said, in real life or via technology, we wouldn't have a very nice world. We'd also start doubting what others said since there are so many people online that just want everybody to feel bad about themselves. Listen to what you want to listen to. 

Take in what you want to take in, and expel what you want to expel. Don't surround yourself with people that make you feel like sh*t. If they do, then they probably never cared for you in the first place. Don't even reply, because the madder you get, the more fun they'll have.