Information already in MI5’s possession in relation to the individual’s previous activity
enabled it, using bulk acquisition data, to conduct analysis to identify the new phone.
Once the phone had been identified, MI5 was able to obtain intelligence through more
targeted analysis; this provided additional information about the individual’s network and
activities. The information led MI5 to conclude that, despite his contact with known
extremists, this individual did not pose a threat in his own right. This conclusion enabled
MI5 to release the resources that had been focused on the individual.
Without the availability of bulk acquisition data, MI5 would have had to undertake a
significantly more time-consuming, costly and intrusive process, possibly including
targeted communications data requests on the individual’s associates, in order to identify
the new phone. This approach would have required additional investigator resource to
make the requests and analyse the results. MI5 also told the Review team that, pending
identification of the new phone, expensive mobile surveillance of the individual would
probably also have been deployed in order to mitigate the threat that this person was
believed to present. Not only would this have been particularly intrusive, but the
deployment of surveillance resources on this individual would inevitably have reduced
MI5’s capacity to obtain intelligence on other threats.
Case study A9/7
MI5
Identify
Counter-espionage
In 2014 MI5 learned that a British national, believed to be engaged in espionage in the
UK for a potentially hostile state, had acquired a new mobile phone. MI5, using bulk
acquisition data, was able to establish that the phone was likely to be one of a small
number of candidate numbers. Further analysis of those phone numbers, involving the
use of bulk acquisition data to identify and analyse the numbers called by each of those
phones, enabled MI5 to identify the phone most likely to be used by the person in whom
it was interested. Without the use of bulk acquisition data, targeted communications data
would have been needed on each of the phones in order to identify the phone most likely
to be used by the individual of interest. This form of targeting of a number of phones, all
but one of which had innocent users, would have been far more intrusive and time
consuming. Identifying the telephone of interest enhanced MI5’s ability to identify activity
of concern; the individual was assessed to present a risk, and steps taken to mitigate
that risk.
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