Democratic presidential candidate Beto O’Rourke has revealed he was a member of a notorious decades-old hacking group.

The former congressman was a member of the Texas-based hacker group, the Cult of the Dead Cow, known for inspiring early hacktivism in the internet age and building exploits and hacks for Microsoft Windows. The group used the internet as a platform in the 1990s to protest real-world events, often to promote human rights and denouncing censorship. Among its many releases, the Cult of the Dead Cow was best known for its Back Orifice program, a remote access and administration tool.

O’Rourke went by the handle “Psychedelic Warlord,” as revealed by Reuters, which broke the story.

But as he climbed the political ranks, first elected to the El Paso city council in 2005, he reportedly grew concerned that his membership with the group would harm his political aspirations. The group’s members kept O’Rourke’s secret safe until the ex-hacker confirmed to Reuters his association with the group.

Reuters described him as the “most prominent ex-hacker in American political history,” who on Thursday announced his candidacy for president of the United States.

If he wins the White House, he would become the first hacker president.

O’Rourke’s history sheds light on how the candidate approaches and understands the technological issues that face the U.S. today. He’s one of the few presidential candidates to run for the White House with more than a modicum of tech knowledge — and the crucial awareness of the good and the problems tech can bring at a policy level.

“I understand the democratizing power of the internet, and how transformative it was for me personally, and how it leveraged the extraordinary intelligence of these people all over the country who were sharing ideas and techniques,” O’Rourke told Reuters.

The 46-year-old has yet to address supporters about the new revelations.