Signal chief has a big warning on AI agents, and it is for all of us

Signal President Meredith Whittaker has warned against the rapid integration of AI agents into operating systems, claiming that the technology poses an “existential threat” to secure messaging apps like Signal itself, Whatsapp, Telegram and others, and the overall integrity of mobile and computer applications. Speaking on the sidelines of the Slush technology conference last week, the head of the privacy-focused apps argued that the rush by major tech companies to deploy agentic AI is creating massive security holes that outweigh any perceived user benefit, she told Fortune.

A new, dangerous attack surface: Whittaker

Whittaker explained that the functional requirements of AI agents is access to large volumes of sensitive, private data, including passwords, bank details and communication records. Whittaker warned that if AI agents gain unrestricted access to sensitive communications and data via the underlying operating system, attackers could easily exploit this new vulnerability.




“The way an agent works is that it completes complex tasks on your behalf, and it does that by accessing many sources of data. It would need access to your Signal contacts and your Signal messages…that access is an attack vector and that really nullifies our reason for being,” she said.

Whittaker criticised the integration of AI agents at the operating system level, calling it a “very reckless and insensitive to cybersecurity and privacy basics” architectural decision. She noted that AI agents are highly vulnerable to prompt injection attacks, where malicious instructions hidden on websites can trick the AI into executing harmful actions.

No one want AI in messaging app

Whittaker also dismissed the idea of integrating AI in messaging, stating, “No one wants AI in their messaging app. It’s really annoying.” Her message comes as rivals like Meta-owned WhatsApp and Facebook Messenger already have AI features. She questioned whether the potential benefits of AI justify the trade-off in security.

Whittaker attributed this rushed deployment to financial pressure. "There is a need to continually float these valuations in this market to investors and shareholders quarterly, leading to what I’m seeing as a lot of reckless deployments that bypass security teams," she said.