individuals other than those covered by the warrant was intercepted. Security
Service staff have been reminded of the importance of maintaining
comprehensive records of the status of communications addresses covered by
warrants.
69. Five separate errors occurred when the Security Service sought
modification of warrants to add new telephone numbers. Due to human error
digits were either transposed or mistyped and incorrect numbers added to the
schedules to the respective warrants. On discovery the numbers were deleted
from their respective schedules. In four of the cases no product was received and
in the fifth case what product was received has been destroyed. Security Service
staff have been reminded of the importance of carrying out thorough checks of
telephone numbers added to interception warrants.
70. The Secret Intelligence Service reported one error when their mail room
sent warrant documents meant for one communications service provider (CSP) to
another. In normal circumstances, the SIS mail room puts correspondence for a
CSP in envelopes which bear a label addressed to that CSP. These envelopes are
then put inside a plastic pouch which also bears a label addressed to the same
CSP. The breach occurred because the inner envelopes were correctly addressed
to the CSP whilst the outer envelope was addressed to a completely different CSP.
New checking procedures have been instigated in the SIS mail room to prevent a
future recurrence.
71. HM Revenue and Customs (HMRC) reported three errors. In the first
case, HMRC made an application for a warrant against a telephone number which
was authorised and interception commenced. Concern was expressed about the
lack of product. A check revealed that HMRC’s application to the Home Office
showed three different digits in the telephone number. Interception ceased
immediately: as already mentioned no product was received. It appears that the
three last digits of the telephone number were transposed as the final print of the
application was made prior to its submission to the Home Office. Manual checks
of the final print are now made in HMRC to prevent future recurrences.
72. The second error occurred in the authorisation of a modification to the
schedule of an interception warrant. A telephone number was identified for a
target which HMRC sought to have added to a schedule to an interception
warrant. Following authorisation, interception of the number commenced but it
became apparent from the product that the mobile telephone was not in the
possession of the target. A check of the paperwork revealed that a typographic
error had been made in the intelligence report upon which HMRC had acted: this
resulted in the identification of the incorrect mobile telephone number. The
intercept was suspended immediately. HMRC reinforced its procedures for
checking source data used in all applications.
73. The third error reported by HMRC was one not of their making nor the
communication service provider. A series of computer upgrades were undertaken,
some of which were not successful. The unsuccessful upgrades resulted in
intercept product which was not relevant to the warranted telephones being
intercepted. This incorrectly delivered product was occasionally interspersed with
correctly delivered product relevant to the particular telephone. Whilst the
majority of the product delivered incorrectly was attributable to other telephones
warranted by HMRC, there was at least one instance where the intercept product
was believed to relate to another agency. These delivery faults were reported and
were rectified with intercept product subsequently being delivered correctly.
74. The National Criminal Intelligence Service reported three errors. An
example of one of NCIS’s errors is when they sought modification of a warrant
to add a new telephone number. Due to human error a digit was mistyped and an
incorrect number added to the schedule to the warrant. On discovery the
interception was suspended and the number deleted from the schedule. No
intercept product was received. NCIS has made improvements to their procedure
to prevent a recurrence of a similar error.
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