TEXT: CORRECTS TO SAY THAT PHOTO WAS TAKEN DURING PREPARATION FOR THE SUMMIT ON WEDNESDAY, NOT THE ACTUAL SUMMIT ON THURSDAY - In this Wednesday, June 21, 2017, photo, Facebook CEO Mark Zuckerberg speaks in preparation for the Facebook Communities Summit, in Chicago, in advance of an announcement of a new Facebook initiative designed to spur people to form more meaningful communities with Facebook's groups feature. (AP Photo/Nam Y. Huh)