BIG BROTHER WATCH AND OTHERS v. THE UNITED KINGDOM JUDGMENT
communications data had to complete a further record explaining why it
was necessary and proportionate to do so, in pursuit of GCHQ’s statutory
functions (see paragraph 6.4 of the IC Code, at paragraph 96 above); and
these records were subject to audit and oversight by the IC Commissioner
(see paragraphs 135-136 and 381 above). According to the Government, it
would not have been feasible to extend the section 16(2) safeguard to
related communications data, since this would have required the Secretary
of State to certify the necessity and proportionality of targeting the
individual concerned in every case. The number of queries made against
communications data was significantly higher than the number of queries
made against content (possibly many thousands in any given week in
relation to individuals known or believed to be in the United Kingdom), and
in many of these cases the identity of the individual would not be known. In
addition, the Government pointed out that related communications data had
a temporal quality, and having to delay the conducting of searches pending
acquisition of an individual authority would seriously risk undermining their
use in intelligence terms (see paragraph 296 above).
421. The Court accepts that related communications data are an essential
tool for the intelligence services in the fight against terrorism and serious
crime, and that there would be circumstances in which it was both necessary
and proportionate to search for and access the related communications data
of persons known to be in the United Kingdom. Moreover, while
section 16(2) contains an important safeguard governing the process of
selecting intercept material for examination, it is noteworthy that in
assessing the regime governing the bulk interception of content, the Court
placed considerably more weight on the existence or otherwise of an
effective mechanism to ensure that the choice of selectors was both subject
to the Convention requirements of necessity and proportionality; and subject
to both internal and external oversight. Therefore, while the Court would
echo the concerns raised in respect of the choice and oversight of selectors
at paragraphs 381 and 382 above, it does not consider that the exclusion of
related communications data from the section 16(2) safeguard should carry
decisive weight in the overall assessment.
422. As for the duration of storage, the Government contended that
related communications data “require more analytical work, over a lengthy
period, to discover ‘unknown unknowns’”. That discovery could involve an
exercise of piecing together disparate small items of communications data to
form a “jigsaw” revealing a threat, and would include the possible
examination of items that initially appeared to be of no intelligence interest.
Discarding unselected communications data immediately, or even after a
few days, would render that exercise impossible (see paragraph 297 above).
423. In light of the foregoing, and in view of the fact that there was a
maximum retention period, which did not exceed “several months”, and the
difference in treatment was objectively and reasonably justified, the Court
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