Users to find out who was affected

Under fire globally for allowing the data breach, social media giant Facebook will start alerting the 87 million users, including 562,455 in India, whose data may have been compromised as the UK-based Cambridge Analytica pilfered them through an app.

The US-based company will send a detailed message at the top of users' news feed, offering information on apps they use and the information they have shared with those apps.

It will also tell people if their information may have been improperly shared with Cambridge Analytica, the data mining firm accused of harvesting personal information of millions of Facebook users illegally to influence polls in several countries.

“As part of this process we will also tell people if their information may have been improperly shared with Cambridge Analytica,” the company said last week.

Facebook users will also have the opportunity to use the link to delete apps and prevent them from collecting more information, CNN reported.

Also, all 2.2 billion Facebook users will receive a link to see what apps they use and what information they have shared with those apps.

Facebook says most of the affected users (more than 70 million) are in the US, though there are over a million each in the Philippines, Indonesia and the UK. It said the total number of potentially impacted users in India (562,455 people) is 0.6 per cent of the global number of potentially affected people.