It's expected that with a show as popular as Game of Thrones, the studio would do some pretty intense things to prevent any leaks and spoilers before the new season premieres.
Sophie Turner, who plays Sansa Stark, touched upon just how seriously producers took secrecy for the final season of the beloved HBO series. Turner spoke with Vulture about the methods and devices used by the HBO series's producers to keep any and everything regarding season eight under wraps, saying, "The secrecy is crazy."
One device Turner talked about was a "drone killer," which seamlessly disabled drones trying to fly over the studio to get information or photos. She stated, "I don't know how it does it. It creates like this field around and the drones just drop."
The actress also explained how HBO changes the name of both Game of Thrones and the actors, so anyone who's passing by set won't know what's actually being filmed. "We have a whole different name for it when we're shooting it. I think this season it was like The Tree of Life or something," she said.
HBO also shoots completely fake and useless scenes as well as multiple endings, so that even the actors don't always know the actual outcome of an episode or season.
According to GameSpot, Game of Thrones 's final season only has six episodes, but each is rumored to be the length of a feature film. Clearly, we're highly unlikely to get any real spoilers about the final season, so we'll just have to wait to see what happens when the series returns in 2019.