This seems rather similar to the ideas presented in Cass Sunstein's Republic.com, published in 2001, at least insofar as people end up surrounding themselves with what we want, rather than need, to see. Quoting the book description: "What happens to democracy and free speech if people use the Internet to listen and speak only to the like-minded? What is the benefit of the Internet's unlimited choices if citizens narrowly filter the information they receive? Cass Sunstein first asked these questions in 2001's Republic.com." I'm not sure that this talk expands much on, or even acknowledges, Sunstein's contributions to this topic. Perhaps his ideas got filtered out.

You can't just cast aside false positives, though. It's as if you're asking what's wrong with murder on the presupposition that nobody is ever hurt.

This particular method of censorship also reverses the burdens of proof. Rather than the government going to court to prove that a defendant has something illegal or that a site should be blocked, it appears that the government has carte blanche proscribe access to sites; presumably people will now need to sue to have their material unblocked, rather than the government suing them. This can be rather burdensome, particularly for people who are on the margins of society.