According to TorrentFreak, a Reddit user said in a now-deleted post that their legal purchase of the film on Vudu landed them an iTunes copy of it the next day. "I pre-ordered Thor Ragnarok on Vudu yesterday and it links it to my iTunes also. But curiously it showed up in my iTunes library this morning (pre-orders shouldn't). And now I can watch the full movie in HD," they wrote. "I obviously downloaded it right away. I know its supposed to come out February 20th." Others then responded that going that same purchase route made the movie available to them in iTunes as well.
Movies Anywhere is a Disney-owned platform that lets users link their iTunes, Vudu, Amazon and Google Play accounts so that any movies they've purchased through those outlets can be viewed all in one place. It's not exactly clear what went wrong in this case, but it demonstrates how tricky cross-service content options can be.
Naturally, pirated copies of Thor: Ragnarok are now popping up all over the place.