The post of phone numbers paired to Snapchat user names comes days after a security research firm identified the vulnerability in the social networking service.
Facebook remains universal favorite, but LinkedIn, Pinterest, Twitter and Instagram also are seeing growth.
Twitter on Thursday faced a wave of backlash after it changed its blocking policies. The company quickly backtracked.
Instagram Direct lets users privately send photos and videos in what is widely considered a shot at trendy messaging app Snapchat.
Twitter said the new capabilities won't increase the number of ads users see in their feeds.
Twitter's head of News -- Vivian Schiller -- reveals some of the thinking behind her company's news ambitions.
From Nelson Mandela to the Harlem Shake, Facebook recaps the year's most-discussed topics around the world.
Almost 2 million users of social networks should be changing their passwords, as stolen login credentials were found on a botnet server.