Zello walkie-talkie app
Personal information of Zello users are sent without encryption over the internet Bahrain Watch

Zello, a "walkie-talkie" mobile app that became extremely popular among protesters around the world, has been infiltrated by Bahrain police through cyber-security flaws. The police used it to arrest 15 pro-democracy activists, according to monitoring group Bahrain Watch.

Zello, a free push-to-talk app that has been downloaded 51 million times and played a big role in Venezuela, Ukraine, and Turkey protests, allows people to communicate with one another, walkie-talkie style, in groups called channels.

According to Bahrain Watch, Bahraini police allegedly intercepted information from Zello and attracted activists into a fake meeting. After the arrest, which took place on 3 September, the 15 activists disappeared, their lawyers reported. Police then posted messages to the channels warning that they were coming to get the other activists "one by one".

"We believe the app was used to arrest 15 activists in Bahrain who have since disappeared," said Ala'a Shehabi, a Bahraini-British political activist and member of Bahrain Watch group. Shehabi also said they believe Zello is misleading users as it does not indicate the free version is unencrypted.

A Bahrain Watch investigation revealed that after subscribing, the username, phone number, and email addresses of registrants are sent without encryption over the internet and can be intercepted and stored by Bahrain's minister of interior.

The Austin, Texas-based app company Zello, which was co-founded in 2011 by CEO Bill Moore, responded to the monitoring group saying that the free version of the app is unencrypted but their full version is encrypted.

"This is not stated on their iTunes page and in fact they promote the app as used by activists
in Venezuela and Ukraine," Shehabi said.

The largest use of the app has been during the Venezuelan protest against the government of Nicolas Maduro. In February, Venezuela's state-run telecoms company, Cantv, blocked access to the push-to-talk app.

Zello supports up to 600 users on a single channel but the largest channel in Venezuela is about 450,000. Moore said it became the number one app in Ukraine for both the iOS and Android operating systems.