Sir Martin Sorrell, chief executive of WPP has highlighted concerns about advertisers looking to use social media following recent concerns about privacy invasion.

With social media sites such as Facebook and Twitter looking to moneytise their operations, Sorrell has highlighted that these sites are more about personal interaction than commercial interaction and compared the experience as being similar to ‘writing letters to our mothers’ than watching television.

He continued to praise the strength of Facebook’s management team but added that the site had ‘screwed up royally’ in maintaining its users' privacy while attempting to introduce advertising previously.

”My view is that privacy is still a social norm,“ said Sorrell. “People are still concerned about it and the invasion of it.”

Sorrell welcomed the investigation into Google’s online advertising system and search rankings by the European Commission  following complaints from made by Microsoft’s Ciao, price comparison site Foundem and French legal search engine fr about the fairness of Google’s search engine rankings as well as the company’s standard terms and conditions, all of which have been denied by Google.

He also described Google as ‘a much more dangerous company as a competitor’ than it was a year ago.

Sorrell  was speaking ahead of WPP’s financial results being released for last year.

Yesterday, Twitter consultant Mark Shaw told The Drum that Twitter’s introduction of advertising could be ‘disastrous’ if it looked to invade its user’s privacy and advertise about their own twitter feeds.