German Chancellor Angela Merkel and British Prime Minister David Cameron jointly opened CeBIT 2014, one of the world\'s largest IT fairs, in western German city of Hanover on Sunday evening.

With Britain as the partner country, the fair will open its gate to business visitors for the next five days. "Datability", technologies that enable the sustainable and responsible management and utilization of big data, is the leading theme of CeBIT this year.

"This is about data, and obviously it\'s also about capability, possibility, responsibility, sustainability," said Merkel in the opening ceremony on Sunday evening.

About 3,400 exhibitors from 70 countries and regions will showcase their latest technologies, products and solutions on big data, cloud computing, mobile technology and business related to social media. Samsung, Huawei, IBM, Microsoft are among the big names of exhibitors. Some 130 British-based companies has registered as exhibitors, according to the fair organizer.

In the opening session of "CeBIT Global Conferences" scheduled on Monday morning, EU Commissioner Neelie Kroes is expected to join discussion with representatives from industry on the topic "Big Data - Big Business or Big Brother?"

In an interview with Xinhua earlier on Sunday, German Federal Association for Information Technology, Telecommunications and New Media (BITKOM) President Dieter Kempf said data security requires efforts from individual, industries, as well as government and legislation.

"Security and safety technologies are available," he said, adding that government should take regulatory measures under a multinational framework as legislation usually cannot be adjusted fast enough according to the speed of technology development.