“SMS is definitely insecure,” said Riana Pfefferkorn, a research scholar at the Stanford Internet Observatory who focuses on encryption and privacy issues. The telecom architecture that enables text messages to be transmitted, known as the SS7 protocol, has vulnerabilities that “leave Americans’ calls and text messages unprotected against malicious snoops,” she added.

“From an encryption policy standpoint, now is an important time to mount a public relations campaign touting the benefits of an encrypted chat app,” Pfefferkorn said. “Americans recognize that they need and deserve privacy and security for their communications, but they may not know that end-to-end encryption is a great way to achieve those needs, or realize that WhatsApp is [encrypted] by default.”

“The company’s many privacy screw-ups have bred a general atmosphere of distrust,” said Pfefferkorn. “People just don’t believe that Facebook actually respects their privacy, and many people don’t even believe that Facebook [and] WhatsApp truly can’t read their WhatsApp messages.”

“Facebook has totally blown it on public trust, and so if the PR strategy in the US doesn’t work, Facebook will have themselves to blame,” Pfefferkorn said.