https://arstechnica.com/features/2020/08/bridgefy-the-app-promoted-for-mass-protests-is-a-privacy-disaster/

The rise of mass protests over the past year—in Hong Kong, India, Iran, Lebanon, Zimbabwe, and the US—has presented activists with a major challenge. How do you communicate with one another when Internet connections are severely congested or completely shut down and at the same time keep your identity and conversations private?

One heavily promoted solution has been Bridgefy, a messaging app that has the financial and marketing backing of Twitter cofounder Biz Stone and boasts having more than 1.7 million installations. By using Bluetooth and mesh network routing, Bridgefy lets users within a few hundred meters—and much further as long as there are intermediary nodes—to send and receive both direct and group texts with no reliance on the Internet at all.