Rory meets Facebook's Slingshot app team
Facebook recently launched Slingshot - a photo-sharing app that requires the recipient to send back an image of their own before they can view the original picture.
The BBC's technology correspondent Rory Cellan-Jones visited the firm's headquarters in Menlo Park, California, where he met the team behind the new service.
He filmed the video above using Google Glass eyewear.
- From the section Technology