India has asked WhatsApp to justify the implementation of a planned feature covering usernames and to freeze the roll-out in its biggest market, escalating a crackdown on messaging anonymity that began with Telegram, according to a government letter. Earlier this week, Meta’s WhatsApp said it had begun a phased global roll-out, including in India, of the feature, which lets users reserve a unique username and eventually message others without sharing their phone numbers. The intervention is an...