Anti-government protesters in Russia followed along on Twitter as opposition leader Alexey Navalny live-tweeted hishouse-arrest violation today. But the real action was on FireChat, where Navalny and his supporters organized protests and exchanged unfiltered communication.

Open Garden, the San Francisco startup that makes FireChat, says activity from Russia has been spiking since yesterday, when Navalny urged his followers to download the free app. FireChat was the top-trending search on Apple’s App Store in Russia today. Downloads in the country began to increase on Dec. 20 after Facebook blocked a page promoting an opposition rally, under pressure from the government’s communications regulator, according to Open Garden.

FireChat, which lets users create chat rooms and communicate anonymously, has become popular among protesters around the world. Aside from anonymity, the app offers an advantage to those in politically unstable regions because it works even when Internet service is down. FireChat uses a technology available on newer smartphones, called mesh networking, that facilitates wireless communication directly between devices. It uses a combination of Bluetooth and Wi-Fi signals to connect with phones running the app. Iraqis flocked to FireChat in June after unrest prompted an Internet shutdown, and protesters in Taiwan and Hong Kong used the app when wireless networks failed.

As President Vladimir Putin faces increasing dissent during Russia's worst economic crisis since 2009, he’s tightened his grip on the flow of information online. Navalny, an adept social networker, condemned his accelerated trial as a government attempt to silence him. He announced his arrest today to his 16,000 followers on FireChat, where his account has been verified by Open Garden. (Navalny has 868,000 followers on Twitter, where is profile is also verified.)

David Fuller's view

If he survives Putin and his apparatchiks, Alexey Navalny would make a worthy successor.