Walking Dead S4The mid-season premiere of AMC’s The Walking Dead is set to air Sunday night, but some Xbox users got a unscheduled sneak peek when Season 4′s ninth episode appeared for free on Xbox Video this morning. It has since been made unavailable to Xbox users. AMC confirmed the slip-up happened but declined to comment on how the incident occurred. The zombie drama is already one of the most pirated shows on air.

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