Social networking sites like Facebook and Twitter should be monitored to prevent their misuse by paedophiles and terrorists, ex-British spy chief said. David Omand, former intelligence co-ordinator in the Cabinet Office, says criminals are increasingly making use of online social networks to communicate, Daily Mail reported. Those responsible for protecting society need to use the technology to keep suspects under surveillance, he said, adding an individual’s account should only be “hacked” into under “certain circumstances”.