Here's a summary of the comments people have made, if you don't want to look through 300+ comments:

(1) JOAN JETT ROCKS.
(2) THIS IS THE BEST SONG EVER.
(3) I LOVE ROCK N ROLL!
(4) BRITNEY SPEARS SUCKS.
(5) The song that plays in the beginning of the video is "Bad Reputation."
(6) This is a cover song. The original was by The Arrows.
(7) Comments about Joan Jett's looks, sexual orientation, gender, etc.

Thanks for watching the video! (less info)