Personal details of Facebook users could potentially be stolen by malicious hackers, BBC's Click discovers. A guide to how a new controversial ad system, Phorm, will work. Plus, an interview with the company's boss and a critic who says the public do not want it. Spencer Kelly investigates the digital legacy we may unknowingly leave behind when we use the web. In her web review Kate Russell tries an online picture editor, reads an interactive story and visits a virtual barber shop.