1.34.

The Review team has had access to all the closed material presented by the
SIAs to the IPT and the ISC, including the records of closed evidence sessions.
We also sought and obtained disclosure of extensive further material from all
three SIAs, including contemporaneous intelligence reports and internal
documentation relating to the utility (and relative utility) of SIA powers.

1.35.

Three members of the Review team spent an introductory half-day at MI5, and
Dr Nowill spent a half-day at GCHQ observing recent developments in technical
capabilities and questioning GCHQ technical staff about them. The full team then
spent a day at MI5, a day at MI6 and two days at GCHQ. In addition, members of
the team, individually or in pairs, had further sessions with each of the SIAs in
which specific technical matters were discussed and further explanations
provided by the SIAs. There has been frequent further contact to follow up on
specific points.

1.36.

During the sessions attended by all four team members, managers and analysts
from each SIA gave presentations during which they explained the uses to which
bulk powers were put (or to which it was wished to put them), and provided
examples in the form of case studies. Review team members were shown
contemporaneous underlying documentation in respect of many of the case
studies, requested further documentation, and had the opportunity to question
those who had been involved in the cases about their decisions, the outcomes
and possible alternative ways in which they might have been achieved.

1.37.

At MI5 and GCHQ, all team members attended practical demonstrations of the
use of bulk powers. The team was shown electronic records of previous
operations, watched analysts at work on current operations and questioned them
closely in relation to the capabilities they were using and their decision-making
processes. Cathryn McGahey QC returned to MI6 to conduct a similar exercise
there.

1.38.

Following the initial meeting at GCHQ, Bob Nowill and Gordon Meldrum made a
further visit in order to examine more deeply the use of bulk data by GCHQ, by
reference to specific examples. They were shown all the material that they asked
to see, witnessed demonstrations and held discussions at working level with
operational staff. One case that they studied concerned the use of bulk
interception and EI in cyber-defence, and the other the use of EI against
overseas-based counter-terrorism targets.

1.39.

We were mindful that EI (particularly at scale) is the newest and most rapidlydeveloping of the powers under review. It seemed to us inevitable that as with
any new technology, teething troubles and wrong turns were bound to be
experienced. Accordingly the full team, and subsequently Bob Nowill and
Gordon Meldrum, took the opportunity to raise with GCHQ staff a number of

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