You can upload anything to cloud storage, the issue comes up when you start sharing it. A Movie company won't come after you because you have Iron Man on your Google Drive (they won't know it's there in the first place, or should not know it's there) , but if you try to download the movie from a torrent or share it out somewhere where they can see it, they may.
Do knot ask about how to download or find illegal content though or the post will be deleted.