[11] He published some of the first security advisories and research demonstrating early vulnerabilities in Unix such as code injection, side-channel attacks, and information leaks, and was a leader in the full disclosure movement.

[18][19] In 2000, after the first crippling Internet distributed denial-of-service attacks, he was invited to meet with President Bill Clinton at a security summit alongside cabinet members and industry executives.

[20] In 2004 Zatko became a division scientist at government contractor BBN Technologies,[21] where he originally worked in the 1990s, and also joined the technical advisory board of NFR Security.

[7][23] In 2015 Zatko announced on Twitter he would join a project called #CyberUL, a testing organisation for computer security inspired by Underwriters Laboratories, mandated by the White House.

During his tenure he ran at least three Department of Defense (DoD) programs known as Military Networking Protocol (MNP), Cyber-Insider Threat (CINDER), and Cyber Fast Track (CFT).

[30] Cyber Fast Track (CFT) provided resources and funding to security research, including programs run by hackers, hackerspaces, and makerlabs.

The program provided an alternative to traditional government contracting vehicles that was accessible to individuals and small companies previously unable to work within the cumbersome and complicated DARPA process.

[2][32][33] Zatko was hired by Jack Dorsey – Twitter's CEO – in November 2020 to lead the company's information security approach, after a July 2020 hack that compromised multiple high-profile accounts.

[38] Zatko accused several Twitter executives, including Parag Agrawal and certain board members, of making false or misleading statements about privacy, security, and content moderation on the platform in violation of the Federal Trade Commission Act of 1914 and SEC disclosure rules.

"[45] Mudge published numerous papers and advisories detailing security problems across different applications and operating systems and was a pioneering champion of full disclosure.