Ahead of its long-delayed American premiere, an unfinished ‘workprint’ copy of “A Minecraft Movie” is circulating on pirate sites. Warner Bros. is trying to contain this and other leaks, but that may prove difficult. The incident mirrors the infamous 2009 X-Men Origins: Wolverine workprint leak and the involvement of the FBI, which led to the arrest and conviction of an uploader. The source of that leak was never publicly disclosed.