It's a new mobile app called Quarantine Watch. The government of the southern Indian state of Karnataka is using it to track people it has placed under home quarantine. To see whether people stay put, the app follows users' movements through GPS — and asks them to submit hourly selfies to prove they haven't left the house.

"A selfie an hour will keep the police away," wrote the authorities in a tweet announcing the app. The only exception is for the time you're presumably asleep — from 10 pm to 7 am. Violators, it warned, would be sent to "a government-run mass quarantine centre."

Quarantine Watch is just one of several apps and other digital surveillance measures that states and the central government have launched to curb the spread of the novel coronavirus. While many Indians have not objected to these measures, human rights activists and lawyers like Murali Neelakantan say the new efforts are highly intrusive, putting people suspected of COVID-19 at risk of stigma and harassment and exposing the country's lack of digital privacy laws.

India's fight against COVID-19 has been complicated by people dodging the quarantine, either leaving their homes because they believe that they don't have the virus or bolting from the centres, which have been criticized by detainees for being poorly run and unhygienic.

So, to ensure that people remain under quarantine, the government has issued new surveillance measures, and they're monitoring them closely using mobile phone apps and other methods. Such countries as South Korea and China have also used apps to track the movements of people put under quarantine.

Another one of these surveillance strategies in India is to publicly release the addresses of people who have been potentially exposed to the virus — a tactic successfully deployed in places like Hong Kong. The idea is for neighbours to keep an eye on people living at those addresses and make sure they remain in quarantine. Citizens are encouraged to confront and report violators to the authorities.

The Karnataka government — proponent of the selfie rule — released the complete addresses of an estimated 20,000 people under home quarantine in the state after having travelled abroad. They withheld the names but published these addresses on the government's official website.

Many Indians praised the efforts of the authorities and felt that the programme would keep them safe from the spread of the virus.

One Twitter user wrote: "Superb plan Sir...kudos to the team who thought this novel idea. At least this will bring some discipline in them."

But the list has had unintended consequences. "The government seems to have released the list in order to ensure that the epidemic does not spread but without any idea of the implications this will have on the personal privacy of individuals," says Karnataka-based Rahul Mathhan, lawyer and author of Privacy 3.0, Unlocking Our Data Driven Future.

The very day that it was published, the list was circulated on WhatsApp groups. Whatsapp has 400 million users in India, providing a far greater audience than those who could view it online. In a matter of hours, some people recognised the addresses and named the residents themselves, circulating the names with "Warning" tags and urging others not to go near those affected homes. As a result, people under quarantine were exposed to public scrutiny and left vulnerable to bullying and attacks.