Marissa Mayer, chief executive officer for Yahoo! Inc., Marc Benioff, chief executive officer for Salesforce.com, Mike Fries, chief executive officer for Liberty Global Plc, Tim Berners-Lee, computer scientist at MIT, and EU’s digital economy chief Guenther Oettinger talk about the outlook for cloud computing, securing personal data on the Internet and steps web-based businesses must take to gain user trust. They speak at a panel event at the World Economic Forum's annual meeting in Davos, Switzerland. Nik Gowing moderates.