38. The third case arose out of a technical fault in the computer system. At the
same time that technical work was being undertaken to remedy a fault in the
database, a GCHQ analyst made an entry on the database for a specific action
to be carried out. Unfortunately the technical work had a subsequent adverse
effect on the accuracy on the working of the database. I understand that
technical faults of the kind that occurred are extremely rare and it was very
unfortunate that it occurred at the same time as the analyst making an entry.
This coincidence of events is very unlikely to happen again.
39. The Security Service reported eleven errors, brief details of six of these are
highlighted below. Errors were reported in two separate cases where, although
the warrants were properly obtained against the targets, product revealed that
the telephone numbers quoted on the two warrants were incorrect and that the
phones were not, in fact, being used by the intended targets.
40. The third error occurred in a case where warrants were obtained against
two targets but the investigating officer had inadvertently transposed
telephone numbers and targets on the individual warrants so that the
interception warrants had the targets names on them with the other target’s
telephone number. It is vitally important that telephone numbers on warrants
are checked very carefully. The Security Service has reviewed its procedures in
the light of this error and has introduced a more rigorous system of doublechecking numbers.
41. In the fourth case, the Security Service obtained a warrant with a mobile
telephone number and a business landline number provided by the National
Crime Squad who themselves were provided the numbers by a covert human
intelligence source. It transpired that the mobile number was incorrect in that
one digit was different. No product was received from this interception.
42. The fifth error occurred when the Security Service omitted to request the
cancellation of a warrant. The Service recognise that this was as a result of
human error despite the use of an IT system intended to help ensure the
effective detailed control of the warrant process. The Security Service are
considering how their procedures can be improved to prevent a recurrence of
a similar error in the future.
43. The sixth error occurred when a warrant contained an incorrect telephone
number: individual digits within the number being transposed incorrectly. No
product from the line was listened to as the transcriber dealing with the case
recognised the mistake immediately and suspended the line. The line was
cancelled and the correct telephone number added to the warrant.
44. The reasons for the remaining five errors occurring include the opening
by a CSP of a letter not covered by an interception warrant; the failure of both
the Security Service’s and a CSP’s system to cancel intercepted lines and the
Security Service intercepting a target’s address which was then discovered to be
slightly different from that quoted on the relevant warrant.
45. The Secret Intelligence Service (SIS) reported one error after they
discovered that a mobile telephone number had been retained on a warrant for
a period of time after the line had been disconnected by the operator. The line
was immediately suspended on SIS’s system and they initiated a warrant
modification to delete the number from the warrant. Although the mistake was
partly due to misinformation they had received from a CSP, SIS have taken
immediate steps to ensure that their working processes are updated to prevent
a recurrence of a similar error. As the line had been disconnected of course no
communications were in fact intercepted after disconnection.
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