I'm going to have to say, this is a bad solution, but a good idea in the long run.
Why?
This could theoretically bring about the end of the worst thing in the internet, Trolling.
Trolling is seriously killing the internet. Essentially, someone could come on to this site, bully everyone just for the lulz and lols, and no matter how many accounts you can ban, they can come back on a friends computer and start harassing everyone all over again. Having been trolled into almost ending my DA account (essentially something bad happening when I needed it the least), I'd love to see something that punishes those fat little 13 year olds who are the biggest losers in the history of history.
But this isn't the right way. SOPA and PIPA were because the entertainment industry wanted a boogieman/scapegoat for their mismanagement that cost them money. This is to end cyberbullies and trolls and make the internet a friendlier place. Just the wrong way to go about it.