Facebook already has apps called Messenger, Whats App and Slingshot, which help users send messages to one another or groups.Its photo-sharing app Instagram allows largely anonymous users to share photos and have conversations.
"The manner and speed with which they contacted us gave us the ability to respond as soon as possible," said Duncan, one of a half-dozen law enforcement officials interviewed who praised Facebook for triggering inquiries.
Gone are the slow-loading square photos overlaid with words; in their place is a Twitter-like feed with snippets of text.
You can still add a photo to your post, but it appears in a circular thumbnail next to the text.
The company's new Rooms app, unveiled Thursday, will allow people to chat in groups.
Users can sign in to the app with an email address or use a pseudonym, and they don't need a Facebook account to join.
Users can post photos, movies and text, and they can even change the company's iconic "like button" to say whatever they want.