Alex Stamos

In 2004 Stamos co-founded the security consultancy iSEC Partners. After NCC Group acquired it in 2010, he formed a research and development division that produced five patents.⁠[1]

He served as an expert witness in the Google Street View incident and did pro bono work in Sony v. George HotzGeorge HotzGeorge Hotz (known online as geohot) is a programmer and hacker who in 2007 became the first to carrier-unlock the iPhone and later faced a Sony lawsuit over his PlayStation 3 hack; he founded the driver-assistance company comma.ai and the AI computer company tiny corp.Open the full entry and United States v. Aaron Swartz.⁠[1]

Stamos briefly served as chief information security officer of Yahoo, where he led the company’s response to the Snowden disclosures and testified before the U.S. Senate Permanent Subcommittee on Investigations.⁠[1][2]

On December 3, 2014, Andreessen HorowitzAndreessen HorowitzAndreessen Horowitz (a16z) is a venture capital firm founded in 2009 by Marc Andreessen and Ben Horowitz. It invests from the seed stage through the growth stage and provides operational support to its portfolio companies.Open the full entry published the podcast episode “a16z Podcast: Security’s Wakeup Call,” recorded at the a16z 2014 Tech Summit. Stamos, then YahooYahooYahoo is an internet brand founded by Jerry Yang and David Filo in 1994, with email, search, news, finance, sports, and advertising businesses. It developed from a web directory into a portal, underwent major acquisitions and security incidents, and sold its operating business in 2017, when the original listed company became Altaba. Apollo-managed funds acquired the brand’s operating business in 2021. Yahoo launched the AI answer service Scout in 2026.Open the full entry’s security chief, discussed the state of security with former U.S. Deputy Secretary of Defense Ashton Carter and a16z board partner John M. Jack.⁠[3]

Set against breaches at Sony Pictures, Home DepotThe Home DepotThe Home Depot, Inc. is an American home improvement retailer, the world’s largest by net sales for fiscal 2025, headquartered in Atlanta, Georgia.Open the full entry, JP Morgan Chase and Target, the conversation covered government-sponsored hacking, the Snowden disclosures and whether companies can respond to increasingly well-armed adversaries. The episode was uploaded to the a16z YouTubeYouTubeYouTube is Google’s video-sharing and creator platform, founded in 2005 by Steve Chen, Chad Hurley, and Jawed Karim and acquired by Google in 2006. Built around video uploading, viewing, and creator earnings, the platform has developed Shorts, YouTube Music, Premium, YouTube TV, and products for children, and is headquartered in San Bruno, California, United States.Open the full entry channel on January 1, 2019.⁠[3][4]

In 2015 Stamos left Yahoo to become chief security officer of Facebook. There he led the company’s investigation into manipulation of the platform around the 2016 U.S. election and co-authored the April 2017 report “Information Operations and Facebook.”⁠[2][1]

In August 2018 it was announced that he would leave Facebook on August 17; the company did not name a new chief security officer and reorganized its security team to work more closely with product and engineering. In his statement Stamos said, “For the last three years, I have been proud to work with some of the most skilled and dedicated security professionals in the world.”⁠[2]

After leaving Facebook, Stamos joined Stanford UniversityStanford UniversityStanford University is a research university in California founded by Leland and Jane Stanford in 1885 and opened in 1891.Open the full entry as an adjunct professor at the Freeman Spogli Institute for International Studies and a visiting scholar at the Hoover Institution, planning a course on offensive and defensive techniques. He was the founding director of the Stanford Internet Observatory at the Cyber Policy Center and is a lecturer in Stanford’s Masters in International Policy program and in computer science.⁠[2][1]

In 2021 Stamos and Christopher Krebs, the first director of the U.S. Cybersecurity and Infrastructure Security Agency (CISA), founded Krebs Stamos Group, which provided cybersecurity consulting to major corporations.⁠[5]

On November 9, 2023, SentinelOne announced the acquisition of Krebs Stamos Group, on undisclosed terms, and formed PinnacleOne Strategic Advisory Group; Stamos became SentinelOne’s chief trust officer and stepped down as director of the Stanford Internet Observatory to focus on teaching and child-safety research.⁠[5]

On August 1, 2024, SentinelOne named Stamos chief information security officer, overseeing its security engineering and operations teams with a focus on secure-by-design systems. “Organizations must be able to trust that their providers are focused on chasing adversaries, not dollars,” he said.⁠[6]

Stamos has served on the U.S. Department of Homeland Security’s Cybersecurity Advisory Committee, the Aspen Institute’s Cyber Security Task Force and the Bay Area CSO Council, is a member of the Council on Foreign RelationsCouncil on Foreign RelationsThe Council on Foreign Relations (CFR) is a nonpartisan, independent U.S. membership organization and think tank founded in 1921 and based in New York, which has published Foreign Affairs since 1922 and takes no institutional positions on policy; Michael Froman has been its 15th president since 2023.Open the full entry, and sits on the advisory board of NATO’s cybersecurity center of excellence in Tallinn. He organized the Trustworthy Technology Conference and OURSA, and has spoken at the Munich Security Conference, DEF CON and Black Hat, where he gave the 2017 keynote.⁠[1][6]