“Good artists borrow great artists steal” is a phrase that Facebook seems acutely aware of. It’s common to speak of Instagram, the Facebook-owned photo-app-now-social-network, borrowing from Snapchat, but now Facebook’s WhatsApp chat app is increasingly drawing its innovation from others such as Telegram. This week, WhatsApp outed a new feature for its groups that is essentially a replica of Telegram’s channels — that is, a one-way broadcast communication stream. Telegram channels are popular for setting up a broadcast news feed that allows people to sign up to get alerts from channel admins, who might be news agencies, companies, schools, public interest groups or more. Now WhatsApp is adding the feature to gives its message app new use cases. Actually, as is often the case for WhatsApp, users have unofficially adopted channel-like behavior for some time. Last year, for example, there were reports of a rural journalist using the messaging app to report and broadcast local news ...