Signal, one of the best encrypted messaging apps around, would leave the UK if a proposed new security Bill becomes law.
In its current form, the UK government's Online Safety Bill would undermine encryption by allowing authorities to check private messages in an effort to halt terrorists and pedophiles online.
Signal said it would rather shut its UK operations than undermine or weaken its privacy policies.
The fight against encryption
"We would absolutely 100% walk rather than ever undermine the trust that people place in us to provide a truly private means of communication," Signal president Meredith Whittaker told the BBC.
"We have never weakened our privacy promises, and we never would."
Launched in 2014, Signal now counts over 40 million monthly active users and more than 120 downloads. The app is very popular for its extra security features, like its disappearing messages mode, especially among those more in need of strong privacy such as journalists, activists and politicians.
Passing now in Parliament, the Online Safety Bill has long been criticized for its plans to undermine encryption. Under the current form, the Bill will give to its body regulator Ofcom the duty to scan encrypted messages for child sexual abuse or terrorism content.
The UK government said the Bill isn't about ban end-to-end encryption, but rather a way to halt criminals lurking online. "It is not a choice between privacy or child safety - we can and we must have both," wrote the Home Office in a statement.
Whittaker doesn't fall for it, though, describing it as "magical thinking" to believe that the Bill could guarantee the privacy of those not breaking the law.
She also pointed out how this could allow both malignant state actors and criminals to exploit this "back door" for their gain.
She said to the BBC: "Encryption is either protecting everyone or it is broken for everyone."
Signal isn't the only app offering encrypted communications out there. WhatsApp, Apple's iMessage, Facebook and Telegram all use E2E to secure users' communications. Security software like VPN and secure email services might be tangled up under the UK law, too.
Even worse, also outside the UK governments are battling against encryption in the name of a safer online world. The EU Chat control, for example, is regulating something very similar to the Online Safety Bill.
Privacy advocates at The Electronic Frontier Foundation also warned about the risks of such law, describing "the censorious, anti-encryption Online Safety Bill" as a possible blueprint for repression around the world.
They wrote in August last year: "The next UK Prime Minister should abandon the bill in its entirety. If they won’t, Parliament should vote to reject it."
