Brian Krebs, the researcher, pointed to the account’s owner based on past postings to the social media side and other Twitter information that led him to believe he’s part of the “Impact Team” responsible for the attack. But Thadeus Zu has spoken out against the accusations, tweeting, “They’re eyeballing the wrong dude here, man,” according to the publication.

Krebs has targeted Zu for numerous reasons, including citing information that Zu has hacked government sites in the past and has played AC/DC songs once the hack was completed. The Ashley Madison hack, meanwhile, had the song “Thunderstruck” played from the company’s computers.

Per the Independent:

He also appeared to tweet links to the huge data dumps from the hacks, before they were picked up by the mainstream media, according to Krebs. Krebs said his initial interest in the account had come about because it posted a link to Ashley Madison source data soon after it was released.

“Thadeus Zu — whoever and wherever he is in real life — may not have been directly involved in the Ashley Madison hack; he claims in several tweets that he was not part of the hack, but then in countless tweets he uses the royal “We” when discussing the actions and motivations of the Impact Team,” according to Krebs.

“But one thing is clear: If Zu wasn’t involved in the hack, he almost certainly knows who was,” added Krebs.