So what would that mean in practice? ISP's would buy into some stupid "great firewall" thing built by, say, McKinsey, that works in the most obvious cases, so they can claim "they're doing their part"?

ISPs would be required to disconnect people who are found to be connected to various torrent sites under the claim that they pirate, then it expands to perfectly legitimate sites, and then the internet becomes useless, and violence breaks out.

The simple claim and bureaucratic framework similar to DMCA would largely bypass the courts and deprive people of their paid services, as well as access needed for various societal tasks (i.e. passports, mail issues, taxes, etc) first without due process. Basically the same as getting an injunction without having to see a judge or provide adequate proof.

In other words the RIAA and their friends, under color of law may become its own kangaroo court or something along those lines.