"We must be allowed to spy on Facebook and Twitter"

The report’s publication comes against the background of intense controversy over the Government’s plans to extend the monitoring of all texts, telephone calls, emails and internet traffic in the UK.

Sir David said that proper regulation was essential to ensure public trust in the system.

‘The problem with social media is that it doesn’t really fit the 19th and 20th century structures we have for how you go about regulating these matters,’ he said.