The U.K. has yet to face the "high water mark" of the terrorist threat, according to the head of MI5, who warned on Wednesday the "scale and tempo" of terrorist activity is at a level unprecedented in his 32-year career. Emphasising that government powers to monitor suspects are vital to preventing attacks, Andrew Parker, director general of the clandestine service, said the danger posed by the Islamic State, also known as ISIL, "shows no sign of abating."
In a speech delivered in London, Parker noted that six planned terrorist atrocities in the U.K. were thwarted in the last year. The director general’s remarks come days before the government publishes legislation on the role of spies within the digital era.
"We are seeing plots against the U.K. directed by terrorists in Syria; enabled through contacts with terrorists in Syria; and inspired online by ISIL's sophisticated exploitation of technology," Parker said. "It uses the full range of modern communications tools to spread its message of hate, and to inspire extremists, sometimes as young as their teens, to conduct attacks in whatever way they can."
Assessing the extent of the threat today, the MI5 chief added: "It may not yet have reached the high water mark and, despite the successes we have had, we can never be confident of stopping everything."
Twin difficulties faced by MI5 are the speed by which radicalisation can occur online, and how unsophisticated plots hatched by members of the Islamic State can be still pose “mass causality” threat, said Parker, who also noted that potent threats from Al Qaeda in the Arabian Peninsula and South Asia still remain.
“All of this means that the threat we are facing today is on a scale and at a tempo that I have not seen before in my career," he said.
On surveillance, Parker said the powers given to security services had to correspond with developing technology.
"Today the conversations of our adversaries are happening on a bewildering array of devices and digital platforms, often provided by companies based overseas," he noted. "And an increasing proportion of such communications are now beyond our reach -- in particular with the growing prevalence of sophisticated encryption."
“We need the tools to access terrorists' communications online just as much as we intercepted written communications and telephone calls in years gone by," Parker added, stressing: "We use data to save lives."
On the upcoming investigatory powers bill, the MI5 chief said the security service did not want "sweeping new intrusive powers" but a "modern legal framework that reflects the way that technology has moved on, and that allows us to continue to keep the country safe.”