Writing for The World Post blog, Sorrell picked growing fears around data security as one of his five thoughts for the year ahead.

He said that: “The public is already concerned about data security and privacy, as technology drives an explosion in the amount of information collected on consumer behaviour.”

But Sorrell believes that spying and phone-tapping allegations in the US and UK “can only intensify those concerns and further erode trust between individuals and organisations on the subject of personal data”.

“Businesses, like governments, are going to have to work harder to show the benefits that ‘big data’ brings to consumers and economies, to educate the public about how that data is handled, and to demonstrate that companies are responsible custodians of people’s information,” he wrote.

“Opt-out is no longer an acceptable strategy. And opt-in has to be clarified and simplified for the consumer.”

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