The chief executive of encrypted messaging app Signal, which exploded in popularity last year during a backlash over rival WhatsApp’s privacy policies, is stepping down and will be replaced on an interim basis by WhatsApp co-founder Brian Acton.
In a blog post on Monday, Moxie Marlinspike said he had decided it was a “good time to replace” himself as chief executive after almost a decade in the role, adding that he felt it was “an important step for expanding on Signal’s success”.
Marlinspike will remain on Signal’s board, he said. Acton, who co-founded WhatsApp in 2009, had “volunteered” to take over as interim chief executive while the group searches for a replacement candidate, he added.
Alongside Marlinspike, Acton co-founded the Signal Foundation, a non-profit organisation focused on developing “open source privacy technology” for communications, and is the parent of the Signal messaging app.
Signal offers end-to-end encryption, meaning messages cannot be intercepted by outsiders. This has made it a staple service for human rights activists, journalists and those concerned with privacy.
Its mainstream appeal grew in early 2021, particularly when WhatsApp spooked users by changing its privacy policies to allow certain payments and transactions data to be shared with its parent company Meta, formerly known as Facebook. The app also got a boost from Elon Musk, the chief executive of Tesla, who exhorted his followers on Twitter to “Use Signal” around that time.
“Signal has grown in adoption and popularity around the world even faster than I imagined,” Marlinspike said. “I’m struck by how boundless Signal’s potential looks, and I want to bring in someone with fresh energy and commitment to make the most of that.”
Nevertheless, Signal’s recent decision to integrate an untraceable cryptocurrency, known as a privacy coin, into its app to facilitate anonymous peer-to-peer payments has raised concerns that it could attract illicit activity, as well as regulatory scrutiny.
Acton, who will take over as interim chief executive as Marlinspike transitions out of the role over the next month, sold WhatsApp to Facebook in 2014 for $22bn.
He left in 2018 following tensions with Facebook founder Mark Zuckerberg over user privacy and a lack of independence from the parent group.
He has since become an ardent critic of the sprawling social media platform, popularising the hashtag #deletefacebook during the Cambridge Analytica scandal.