Copyright troll
Someone who makes money from threatening copyright lawsuits rather than from the works themselves.
It's the patent troll's cousin. Harvest IP addresses from BitTorrent swarms, get a court to order the ISP to hand over subscriber names, then send letters demanding a "settlement" well below the cost of defending a case. That the subscriber may not be the person who downloaded anything matters little when the sum is chosen precisely so that paying is cheaper than fighting. The British call it speculative invoicing.
Righthaven bought rights to newspaper articles in 2010 to sue bloggers and litigated itself into insolvency. Prenda Law went further, uploading films itself so it could sue the people who downloaded them; attorney Paul Hansmeier was sentenced to 14 years in prison in 2019. Swedish ISPs were hit with disclosure orders in the late 2010s, and Bahnhof made a show of fighting back.