Britain is locked in a post-Snowden ‘ arms race ’ with terrorists who are using technology to spy on the security services and put ‘ our people and agents at risk ’ , the head of MI6 warned last night . In his first public speech , Alex Younger made a series of pointed references to how UK intelligence agencies operate within some of the strictest laws in the world while our enemies were ‘ unconstrained ’ . His comments will be seen as a rejection of the barrage of criticism aimed at MI6 , MI5 and GCHQ by US ‘ whistleblower ’ Edward Snowden and his supporters in the UK . Snowden ’ s cheerleaders claim he exposed mass unauthorised surveillance by the security services . MI6 chief Alex Younger said Britain was locked in a post-Snowden ‘ arms race ’ with terrorists who are using technology to spy on the security services and put ‘ our people and agents at risk ’ But Mr Younger said : ‘ What really distinguishes us from our opponents is that we live by the values of this country and are regulated by its laws , even as we work in secret. ’ He warned that terror groups such as Islamic State and Al Qaeda were increasingly using the internet to target the intelligence agencies . Spy chiefs say the leaks revealed by Snowden – who stole 1.7million classified documents – had revealed sensitive intelligence gathering techniques . Sources have also warned the Snowden files may have put individual agents in danger by revealing their identities or location . Mr Younger said : ‘ The internet and big data can combine to our advantage , allowing us to know more about the people we meet and the places we meet them . Using data appropriately and proportionately offers us a priceless opportunity to be even more deliberate and targeted in what we do , and so to be better at protecting our agents and this country . That is good news . Edward Snowden – who stole 1.7million classified documents – revealed sensitive intelligence gathering techniques . ‘ The bad news is that the same technology in opposition hands , an opposition often unconstrained by consideration of ethics and law , allows them to see what we are doing and put our people and agents at risk . ‘ So we find ourselves in a technology arms race . Contrary to myth , human intelligence operations are not an alternative to technical operations ; the two are interdependent and are set to become more so. ’ The spy chief did not mention Snowden by name . But , in a speech earlier this year , his predecessor Sir John Sawers said : ‘ Snowden threw a massive rock in the pool . The ripples from that have still not died down. ’ Earlier this month , Home Secretary Theresa May added that the leaks by Snowden had ‘ damaged ’ intelligence agencies across the world and drained Britain ’ s spies of vital resources . Mr Younger was speaking at the unveiling of an English Heritage blue plaque at the home of the first MI6 chief , Sir Mansfield Cumming . Known as ‘ C ’ due to his habit of initialling his papers , Sir Mansfield lived and worked at 2 Whitehall Court in Westminster at various times between 1911 and 1922 . Mr Younger said : Naturally , he would be as taken aback as any of his contemporaries at the way in which Britain ’ s role in the world has altered . It fell to him to protect Britain ’ s interests as an imperial power during a great war . My task is a bit more subtle , but no less taxing . ’
MI6 boss Edward Snowden warns about threat posed by new technology . He said intelligence services were restricted by law unlike terrorists . Comes after former US spy Alex Younger stole 1.7m documents . The massive leak revealed sensitive intelligence gathering techniques .