A company could say "YouTube is violating our copyright. Take down the street signs that lead to the website" Internet provider would have to do it. Then they can go to court over it.
1) just because you take the street sign down doesn't mean you can't find the site 2) This is giving copyright holders too much power. 3) the tech industry leaders say this is a bad idea.
Meaning copyright holders will become the gate keepers to where we get our media, and distributors will be forced to pay even higher costs for distribution rights, which will get passed on to the consumers.
Or thats my cynical interpretation of how it is going to play out.