Yolo is fine with me, it's got a great message: live life to the fullest. But a lot of people use it as an excuse to do stupid stuff. You never hear people say, "Going to donate $50.00 to charity, yolo". You always hear "Going to get high, yolo", which makes me sad because people don't use it correctly...
No, that's probably what it is in America, here where I live you're yoloswag when you are daring. Like if you're out with your friends, spot a nice chick, then your buddies go "yolo, son", and you have to transcend swag and get the courage to go talk to her. Or when you dare jump off the highest platform at a swiming pool. Or when you go skydiving.
I don't see why it would be associated with dubstep, I hate that kind of music, I'm a heavy metal fan and also follow the yoloswag mentality.
YOLO is an initialism for You Only Live Once.
"You Only Live Once" is an old saying, and a fine one at that, but initialising it to YOLO and then plastering that all over the place is what gets on some of our nerves.
I'm a bit confused on 'swag' as it's being used here, though. To me 'swag' is synonymous with 'bling', it's decorative jewelry. So... what the heck is YOLOswag??