On Wednesday night, all of HBO’s social media pages—from its company Twitter and Facebook accounts to those belonging to its stable of hit shows like Game of Thrones and Last Week Tonight with John Oliver—began displaying curious messages.

“Hi, OurMine are here, we are just testing your security, HBO team please contact us to upgrade the security,” read the first communication, followed shortly thereafter by “let’s make #HBOHacked trending!”

The premium cable network’s social media had been taken over by OurMine, a self-described “white hat” hacking group that has a reputation for penetrating internet systems to point out their glaring vulnerabilities whilst advertising their cybersecurity services. It marked the latest in a string of cyber setbacks for HBO, who are currently being blackmailed by hackers that managed to make away with 1.5 TB of company data. Thus far, the perpetrators have leaked various portions of the hack in order to pressure HBO to meet their demands, including a network executive’s emails, TV scripts, and several unreleased episodes of their shows, from Game of Thrones and Insecure to part of the upcoming season of Curb Your Enthusiasm.

“It’s funny, because last year we spent so much time and there was so much hoo-ha about email security because there had been a leak the year before. We had to send out for the scripts, get all-new email accounts, get two-step verified, and all this. It was just bizarre,” Nikolaj Coster-Waldau tells me.

Coster-Waldau, of course, is one of the stars of HBO’s crown jewel, Game of Thrones, where he plays the dashing scoundrel Jaime Lannister, aka the Kingslayer. The previous leak he’s referring to came in 2015, when the first four episodes of Thrones’ fifth season made their way online shortly after the premiere.

The 47-year-old Dane, who is one of the highest-paid actors on television, says HBO recently informed him that the hackers have all of the Thrones cast members’ personal information.

“A couple of weeks ago, I get a call from one of the HBO execs and they go, ‘Hey! How are you?’ and at first I was thinking, ‘Oh, I’m being killed off [Thrones]! I’m not going to make it to Season 8,” Coster-Waldau recalls. “But then they go, ‘You know, we just want to inform you that we had a hack. It’s kind of a big problem with HBO. We don’t know quite how bad it is, but it looks like all of your guys’ info has been leaked.’ And I went, What? And they said, ‘Oh, your emails, your phone numbers, all of the info is out there.’ I said, ‘That’s not good! What are we gonna do?’ And they go, ‘Well, we don’t know.’”

I sat down with Coster-Waldau in New York to discuss his excellent turn as a tattooed prisoner in the upcoming film Shot Caller (a longer piece on the film will run early next week). When I ask him if he’s going to have to change all of his personal information, including his credit cards and phone numbers, he shrugs.

“Well, I’m waiting to find out. They told us they were gonna call us and let us know what to do, and they haven’t. So I guess they’re still trying to figure it out,” he says.

The hackers have reportedly demanded $7 million from HBO to stop the leaks, while the network—according to an email obtained by CNBC—countered with $250,000 in bitcoin, which a source told the news organization was just a “delay tactic.”

“See, that’s a problem,” Coster-Waldau says of the $250K offer. “If you already say you’re going to offer them something, then you’re already saying that you’re willing to pay.”