In its monthly report, Meta owned WhatsApp revealed that it banned over 2.39 million accounts in India. The ban was due to India's strict IT laws (pdf) that require digital platforms to publish compliance reports every month.
Out of the 2.39 million accounts, 1.42 million were "proactively banned", before any reports from users. WhatsApp says that in addition to responding to user complaints via greivance channel, it also deploys tools and resources to prevent "harmful behavior" on the platform. This is why, the company says, it is focused on prevention of things that could go wrong.
We believe it is much better to stop harmful activity from happening in the first place than to detect it after harm has occurred.
Apart from the ones that were banned proactively, WhatsApp allows users to report someone within the app. After a report is submitted against a user, WhatsApp recieves the most recent messages sent to the complainant by the reported user or group, as well as information on the complainant's recent interaction with the reported user.
WhatsApp has been strongly criticised as a mean to spread fake news and hate speech, not just in India, but elsewhere in the world as well.