Residents and business owners in areas gripped by violent looting last month used Zello to coordinate and keep one another informed about the movements of rioters.
However, the looters soon started downloading the app themselves and used it to help them find vulnerable targets, MIT Technology Review reported.
Zello is a push-to-talk voice communications app that mimics the functionality of walkie-talkies.
It saw 180,000 downloads during the week of public violence and looting that gripped KwaZulu-Natal and parts of Gauteng in July.
The app is organised into channels where users can talk to one another by recording and sending audio files — similar to voice notes in WhatsApp group chats.
As the civil unrest continued throughout the week of 11 July, Zello communities were warned that looters were listening in on channels to try and figure out which areas were most vulnerable to attack.
Guys please be advised that looters are listening in on Zello chats and using it to find weakpoints in certain areas
— Post Alone (@javharsingh) July 14, 2021
Last month’s public violence started after former President Jacob Zuma was found in contempt of court and turned himself over to Correctional Services in Estcourt on 8 July.
That weekend, on Saturday, 10 July, set several trucks alight at Mooi River in KwaZulu-Natal.
This was followed by blockades of roads and the looting of shops in eThekwini and Pietermaritzburg.
By 12 July, mass looting and vandalism had broken out throughout the greater Durban area and parts of Gauteng.
Looters not only emptied store shelves and warehouses but left a path of destruction in their wake, even setting buildings and storage units on fire.
Over 300 people were killed during the unrest, including several murders in the communities of Phoenix and Verulam, which police are investigating.
With police clearly overwhelmed, communities took it upon themselves to protect their malls and other businesses.
Zello, which was originally designed to help people coordinate and communicate after natural disasters, has been widely adopted among community policing groups in South Africa.
As a voice-first platform, Zello vice president of operations Raphael Varieras said it is faster than typing and doesn’t require literacy skills.
It’s also anonymous. Unlike WhatsApp, you don’t have to expose your phone number to group participants to exchange messages.
Zello offers several security features that may help channel administrators avoid adversaries using the system against the very communities they are attacking.
“Zello has a wealth of tools to make channels a safe place for people to join and communicate with each other, but the creator has to set up the channel correctly and be aware of what the channel can provide,” Varieras said.
This includes requiring that participants have their phone number and email verified.
Administrators can also set a password on specific channels and limit the number of participants.
Channel owners can then change the password as frequently as needed, and current users won’t need to re-enter the password.