OK, there’s the potential for abuse. That’s nothing new
Stephen, let’s just say for the sake of argument I don’t like you. You’re my neighbor and I hack into your wifi router without your knowledge. What’s to stop me from downloading files using a reverse blocklist to be sure I target all the worst sources and continue to do it until you lose your Internet access? Nothing.
Then when you get a different ISP (if they let you), I repeat the same thing until you are effectively banned from the Internet.
Potential for abuse, indeed.