https://www.cnbc.com/2018/10/31/facebook-introduces-workplace-domain-to-calm-enterprise-security-fears.html

On September 28, the day that Facebook disclosed a security breach impacting millions of its users, the head of the company's upstart enterprise business reached out to Walmart, a top customer, to assure it that its data had not been exposed.

Walmart is a customer of Workplace by Facebook, a work version of the social network that companies pay for so their employees can communicate using Facebook-style features, such as private messaging, news feed posts and live streams. The service, which competes with Slack and other enterprise communications services, is used by 30,000 organizations, including Starbucks and Chevron, according to the most figures Facebook shared in October 2017.