6.16.
Of the remaining two identification cases:
(a) Interrogation of communications data obtained by bulk acquisition swiftly
revealed in one (A9/2) that the person behind a threat was a known hoaxer.
(b) In the other (A9/6), an individual, once identified, was assessed not to pose a
threat.
There is a clear value in the use of bulk powers to eliminate lines of enquiry, so
that resources can be concentrated elsewhere and disruption to the public
minimised.
6.17.
A9/8-16 illustrate the Understand category of SIA activity. All these case studies
concerned Islamist extremist activity in the UK and, to a lesser extent, overseas.
In each case, bulk acquisition was used by MI5 to learn more about the activities
and plans of an individual or group. Inevitably, there is an overlap between the
Understand and Action categories; in many cases, the understanding gained by
MI5 led it, itself or with partners, to take action. A9/10 demonstrates the overlap;
in this case, MI5 was able, using bulk acquisition data, swiftly to learn more
about the individuals responsible for the failed attacks in London and the attack
on Glasgow airport in 2007; MI5 was then, using this intelligence, able to support
the police in responding to the attacks and to the threat of further attack.
6.18.
A9/17-25 are examples of action being taken to counter Islamist extremist
activity, dissident Irish republican threats, weapons proliferation and espionage.
Again, there was often no clear dividing line between the categories of Identify,
Understand and Action. Frequently, and as one would expect, one led swiftly to
another. Many of these case studies (and some of those placed in the
Understand category e.g. A9/10-12) involved cases in which individuals were
prosecuted. It would be wrong to say in any of these cases that it was only
through the use of bulk acquisition data that prosecution became possible: as the
SIAs emphasised repeatedly, most operations involve a combination of
intelligence-gathering techniques, and the police involvement in the obtaining of
admissible evidence is crucial. It can, though, be said that the use of bulk
acquisition played a significant role in the cases shown to us in which
prosecution followed.
6.19.
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The case studies demonstrate that bulk acquisition provides MI5 with a valuable
means to obtain intelligence quickly. GCHQ told the Review team that bulk
acquisition was generally not a viable alternative to bulk interception for overseas
operations, because GCHQ would have to rely on the co-operation of overseas
CSPs.221 In MI5’s UK-based operations, the same disadvantage in the use of
See further, 5.34 above.
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