If they prosecuted people for downloading or uploading things with no clear copyright holder or has been off the market for years or unavailable in one's country of residence, that would be one thing, but if it's a simple case of people wanting free 'rentals' or wanting to posess things theat they don't want to put aside some snack money for, I'd leave it between those folks and the law makers.
Outlawing multi-region DVDs would be bad but not nearly as bad as other things still allowed to be outlawed in America.
I can't get GrindHouse on DVD (without importing it from the East)? Too bad. Not as bad as people going to prison for what they do in their own bedrooms or women being labled sex offenders for 'immodesty' or what have you. It might be up there for people who are hardcore fans(though not hardcore enough to put money in an artist's pockets or those of the publishers).
If this thing hasn't already completely fallen through thanks to its own general lack of importance during a global economic downturn, it isn't really worth taking a stand on beyond maybe one of those pointless internet petitions.(Did Left4Dead 2 come out? Yes. Is Wuzzles on DVD yet? No. Did they free Tookie? Death frees the soul, so to speak. That's how effective those things are.)
Pirating kills small businesses, beggars new artists...yadda yadda yadda. I don't need to go over all of that. It ought to be obvious. Even the big companies deserve the money for providing what people want.
If the sharers own the copyrights, there is no problem to begin with, so this isn't going to 'kill the internet'.