Utterly childish to even pay attention to such comments, you were wise to not even say anything as a reply, I've seen plenty of stuff such as this over the years and now I don't even care what they think of it, besides, he's obviously saying this because he's got nothing better to do with his life.

Probably just a little kid wanting some attention, and even relpying to this would've meant lowering yourself to his level, I'm sure you're a lot better than him. If he ain't liking your vid, then why is he even watching it and posting a comment in the first place ??

It's as I was told before years ago: Don't feed the troll.

Just let it go, and eventually out of frustration in not getting any attention out of you, he'll just end up giving up on trying to annoy you any further.

As for Cyber-Bullying, now it's a different story, in my area it's already enough to send the culprit to jail, depends on the area and country you live in though.