Christopher Hadnagy founded Social-Engineer LLC and, starting in 2009, helped create and run DEF CON's social engineering village and related capture-the-flag competitions. In February 2022, DEF CON organizers permanently banned him, citing Code of Conduct violations in a transparency report that did not detail the specific allegations; Hadnagy publicly disputed the ban. He subsequently left or was removed from the Black Hat review board, and after Security BSides Cleveland listed him as an unannounced speaker that June, several other speakers withdrew and the event's organizer resigned.
In August 2022, Hadnagy and Social-Engineer LLC sued DEF CON and its founder, Jeff Moss, for defamation and related claims, seeking at least $50,000 in damages plus equitable relief, and denying any wrongdoing. In March 2024, U.S. Magistrate Judge Brian Tsuchida dismissed six of the seven claims but allowed the defamation claim to proceed. During the litigation, DEF CON's February 2025 motion for summary judgment and supporting exhibits made public detailed misconduct allegations from more than a dozen people, including former employees Maxie Reynolds, Michelle Fincher, Cat Murdock, and Samantha Gamble, who described a pattern of workplace anger outbursts, public humiliation of staff, sexualized comments about female coworkers' appearance, and, in one account, a thrown phone.
On May 13, 2025, Judge Tsuchida granted DEF CON's motion for summary judgment and dismissed the case with prejudice. The court held that truth is a complete defense to defamation and that Hadnagy, as plaintiff, had not shown the implication that he was banned over sexual misconduct was false; it found that question dispositive regardless of what evidence DEF CON held at the time of the ban. DEF CON called the ruling a "victory" for attendees and said on social media it hoped the outcome would make people "feel safe reporting violations." Hadnagy said he was "disappointed" with the decision but relieved to be able to "speak openly about what really happened," and said he wanted Moss to acknowledge the ban stemmed from "workplace bullying and leadership concerns" rather than sexual misconduct.
After the case was resolved, Exhibits five and beyond to the case were published which contained witness statements against Hadnagy, detailing past incidents. The deposition of Hadnagy himself shows admitting to talking about "ball slapping" in classes with paying students, pulling a switchblade in class, that "boobs have superpowers", referring to a female former employee as an "awful psycho bitch", referring to a female employee as "TMA" meaning "the marketing Asian" and later as "adorable little Asian teapot", arbitrarily accusing someone as a "pedophile", and considerably more detailed accounts of how he treated students and women in particular.
