https://www.theguardian.com/media/2017/aug/17/game-of-thrones-secrets-revealed-as-hbo-twitter-accounts-hacked

After initial hack and ransom request, TV network suffers separate breach of social media accounts amid embarrassing leaks of unaired shows

Several HBO Twitter accounts were hacked and taken over by the notorious OurMine hacking group, posting #HBOHacked messages and warnings about security.