The problem legally is Blizzard is going to have an extremely hard time proving a private server user downloaded an unauthorized copy of WoW from a third party

The problem legally is Blizzard is going to have an extremely hard time proving a private server user downloaded an unauthorized copy of WoW from a third party rather than from Blizzard themselves when the version they are playing was the live version. There are a lot of nuanced stipulations involving the legal distribution of the Wow client: * The game has always been distributed using peer to peer seeding, such that Blizzard has never been the exclusive provider of game data, they just told users where to get the data from. * Blizzard has in several cases (mostly early on) recommended users download whole copies of the game from third party websites like fileplanet back in the day when the servers were overloaded with players updating to new versions of the game. * Blizzard has always made WoW available as freeware, and has never auth-gated the download pages before the Battle.net launcher. Old versions of the game used to have installers hosted on Worldofwarcraft.com that anyone could download with a URL regardless of being signed in or not, and users could make accounts without buying the game anyway. This isn't some classical "game developer sells copies for money and people were sharing copies without permission". Today, anyone sharing WoW clients through torrents is obviously violating blizzard IP, but the distribution methods of the client in the past, combined with the fact no player needed to have an account or paper trail showing they had a legit "claim" to the game to have the client, means they cannot realistically argue that anyone playing a private server also violated their copyright on the client. They could have easily obtained it legally, and just changed the home server to a private one so it never updated. That is a violation of the ToS in the game, but not an IP violation, and ToS are civil matters that are often not even upheld in court when tested, and WoW has a fairly grandiose ToS if it were ever put in a real trial.