David Nutter, who directed half of Game of Thrones’ final six episodes, said the security on set was increased to the highest level for Season 8, to keep any secrets sealed shut.
In an interview with Huffington Post, Nutter said, “Well, sometimes there were paparazzi in amazing places ― on construction cranes and all kinds of crazy places, to try to get a point of view of things. They were all over, everywhere, trying to get in on what was happening.”
“But it was definitely a situation where there was no paper on the set,
type of thing,” he continued. “
Source: IGN.com Game of Thrones Security Heavily Increased for Season 8