Frankly, with the amount of bullshit blacklists out there that real mail providers actually trust, I've come to detest blacklists more than spam.

Has anyone set up a blacklist full of random IPs as a joke to see how many people follow it?

Well, we have been put on blacklists that the operator wanted money to "expedite" removal from. I'm assuming that blacklist was pretty much random IPs... And it did impact deliverability.