They could easily get moles into every single private trackers Maybe if they actually wanted to, but what actually happens is they hire a much smaller company that monitors public trackers and sends them thousands of “successful” takedowns. When have you seen private trackers taking down torrents due to DMCA? It pretty much never happens, even for public ones these days the best case for these companies is to get google or other search engines to remove torrent sites from results. You are giving these corps WAAAY too much credit, they only target the lowest of low hanging fruit (ISPs and search engines) because anything else is a waste of time and money. There’s a reason you don’t hear about many lawsuits against private individuals anymore, its because they know its a bad idea to go after “Joe Schmo NoBody” with a net worth of $217 in the bank, who will just declare bankruptcy after the corp spends tens or hundreds of thousands of $ on lawyers for a single case.