Blizzard is clamping down on World of Warcraft multi-boxing.
Multi-boxing is a controversial method of farming online video games for resources that involves one user playing multiple accounts simultaneously. Blizzard is clamping down on one particular method of multi-boxing: using third-party software to "broadcast" your inputs across multiple clients. This key cloning software automatically mirrors a single keystroke or action across multiple versions of an MMO, thus letting the user gather materials and in-game gold at a game-breaking pace.
Players have used third-party software to multi-box in World of Warcraft for years, seemingly within the game's Terms of Service. All that has changed now, though. In a post on the World of Warcraft website, seemingly proclaimed by a watchful Malfurion from upon high, Blizzard announced its upcoming clampdown on third-party input broadcasting software.