Noted "white hat" hacker Peiter Zatko is the new head of security at Twitter (TWTR). Known to many by his hacker handle "Mudge," Zatko confirmed the appointment in a tweet on Monday.

"I truly believe in the mission of (equitably) serving the public conversation," he wrote. "I will do my best!"

Two hackers seated at a desk and working.

Image source: Getty Images.

One of the more high-profile "ethical" hackers on the scene, Zatko has had a long career in security work both in the private sector and in the government. He held positions as security chiefs for privately held fintech company Stripe and the Advanced Technology and Projects skunkworks at Alphabet's Google.

In the public sphere, he was a program manager at the Defense Advanced Research Projects Agency (DARPA), conducting research activities and doling out grants for cybersecurity projects.

He rose to prominence in the 1990s, when he was a top figure at a veteran hacking collective known as the Cult of the Dead Cow. This group gained notoriety for developing and distributing tools that allowed users to hack Microsoft's (MSFT 0.37%) Windows operating system, although the main aim was to pressure the company into improving its security regime. 

The Cult is also known for coining the term "hacktivism," describing positive hacking done for the benefit of society.

Zatko's skills should get quite the workout at Twitter, which has struggled with security vulnerabilities. This past July, for example, a group of hackers accessed internal tools at the company. They then used them to change account settings and send fake tweets from prominent accounts such as those of Joe Biden, Tesla CEO Elon Musk, and Microsoft founder and ex-CEO Bill Gates.