Twitter challenged Meerkat—a start-up that gained traction at this month's South by Southwest conference—by launching Periscope last week.
A bunch of celebrities including Jimmy Fallon to Jared Leto jumped on board to broadcast live messages to their followers.
When three buildings collapsed and ignited a blaze in New York last week, these smartphone apps brought the live video feed to anyone online wanting to watch.
The event showed how Periscope and rival app Meerkat, which can deliver live video through Twitter to anyone online, could become an important tool for citizen journalism.
By feeding live video through Twitter to anyone online, these apps eliminate the need to upload to YouTube or transfer to broadcasters like CNN to get a wide audience.
While social media has empowered citizen journalism for years, the use of live video could become a powerful tool for these reporters and change the way people get news.