Who are Signal’s founders Moxie Marlinspike and Brian Acton? Marlinspike took to X to respond to Trump’s US military group chat fiasco, and Acton is the billionaire who sold WhatsApp to Facebook

Mar 27 , 2025

Moxie Marlinspike and Brian Acton created the non-profit Signal Foundation together in 2018. Photos: @moxiemarlinspike, @adcavepk/Instagram

The Signal Foundation’s co-founders Moxie Marlinspike and Brian Acton both have a background in tech: Acton created WhatsApp before selling it to Mark Zuckerberg for billions – but later regretted it

Signal’s founder Moxie Marlinspike has responded to the US military group chat fiasco by taking to X to poke fun at President Donald Trump’s administration.

“There are so many great reasons to be on Signal,” Marlinspike, whose real name is Matthew Rosenfeld, wrote on X on Monday afternoon.

Moxie Marlinspike, co-founder of the Signal messaging app, made a wry joke on X about the Signal group created by National Security Adviser Mike Waltz. Photo: @moxiemarlinspike/Instagram

“Now including the opportunity for the vice-president of the United States of America to randomly add you to a group chat for coordination of sensitive military operations. Don’t sleep on this opportunity …”

US vice-president J.D. Vance, defence secretary Pete Hegseth and national security adviser Mike Waltz all shared classified information on a Signal group chat. Photo: Reuters

Earlier that day, The Atlantic’s editor-in-chief Jeffrey Goldberg had revealed that he had been accidentally included in a Signal group chat with US national security leaders discussing upcoming military strikes in Yemen.

Smoke rises from a location reportedly struck by US air strikes in Sanaa, Yemen on Saturday, March 15. Photo: AP

Two hours after he received details of the attack on March 15, the US began launching air strikes against Houthi targets in Yemen. The group chat reportedly included defence secretary Pete Hegseth, vice-president J.D. Vance, secretary of state Marco Rubio and Tulsi Gabbard, Trump’s director of national intelligence.

Moxie Marlinspike originally co-founded a company called Whisper Systems. Photo: @moxiemarlinspike/Instagram