First the positives. This was funny. An old woman singing a RATM song is a funny thought on its own, but when put into animation (my favorite entertainment medium) its even funnier. Also, I found the use of the "Fuck you, I won't do what you tell me!" part to have been used to its best ability.
Now for the negatives. The animation is lazy as all hell and is out of rhythm with the song and voice acting. It also could use some work on its animation style, and before you jump at me saying "But Pixel, my fans won't like my animations as much then.", don't worry. I've seen it done very well before in the cases of FilmCow and MondoMedia (although MondoMedia is an animation hub, but 1,000,000+ subscribers don't lie). The audio could use work too. I know this might just be me with my volume turned down too low, but in some cases I couldn't hear what Susan was saying "And now you do what they told ya." and "Fuck you, I won't do what you tell me.". The voicing could use some work too, but I have seen mediocre voice acting done well in the MondoMedia series "World Doctors" which you should check out by the way, and take notes if you don't plan on changing your animation style.
All in all, I did enjoy this. I laughed pretty hard at the "Fuck you, I won't..." okay you get it... (insert awkward pause here) *cough* part. You do have the comedy part right, but the overall production isn't very well executed. I award you 3/5 stars. I noticed Scott Ian, Miley Cyrus, I think Kerry King or someone else from slayer and I think I saw Tom Morello as one of the judges.