Zuckerberg has just promised Senator Maggie Hassan that Facebook will work with Congress towards a suitable framework of regulation.

However, he doesn't quite agree when Hassan suggests introducing financial penalties for breaches. He says Facebook already has a financial incentive to do things properly.

"This episode has clearly hurt us," he says. "And has cleary made it harder for us to achieve the social mission we care about. We now have to do a lot of work to build trust back."