too high. By way of example, details of some of these errors are recorded below.
It is very important from the point of view of the public that I stress that none
of the breaches or errors were deliberate, that all were caused by human error
or procedural error or by technical problems and that in every case either no
interception took place or, if there was interception, the product was destroyed
immediately on discovery of the error. The most common cause of error tends to
be the simple transposition of numbers by mistake e.g., 1965 instead of 1956. The
examples that I give are typical of the totality and are anonymous so far as the
targets are concerned. Full details of all the errors and breaches are set out in the
Confidential Annex.
2.11 The Northern Ireland Office/Police Service Northern Ireland reported
four errors. In one case, an incorrect telephone number was cited on the warrant
due to the transposition of digits but no product was received.
2.12 Six errors were reported to me by GCHQ of which three are highlighted
below. The first case involved an analyst mistyping a telephone number into
GCHQ’s targeting database. During the period the number was the subject
of interception no calls to or from the telephone were intercepted. The analyst
has been reminded of the importance of accuracy in entering numbers into the
targeting database.
2.13 The second error occurred during a fast paced incident. Because of the urgency
of the situation the telephone number provided by an official source was accepted
in good faith and the number added to an existing warrant by a senior official.
Unfortunately when a sample of the calls was analysed they were found to have no
intelligence value and to involve conversations between two unidentified people.
Consequently, the calls that were recorded were deleted from GCHQ’s systems.
2.14 The third error was caused by a technical problem with an automated process
which resulted in an instruction to remove two numbers due for deletion not being
passed to all GCHQ’s call collection systems. Other numbers deleted from the
same warrant at the same time were successfully removed. The computer software
controlling this process has subsequently been improved.
2.15 The Security Service reported eight errors. Brief details of three of these are
highlighted below. In the first case the Security Service processed a modification
to add a new mobile telephone number to an existing warrant. Unfortunately
the submission with the new telephone number included an incorrect telephone
number. This resulted in the wrong telephone number being intercepted. The
number was subsequently deleted from the warrant; no product was obtained
and there was no interference with privacy. Security Service officers have been
reminded of the importance of carrying out thorough checks of telephone numbers
added to interception warrants.
2.16 The second error occurred when a target changed his mobile telephone
number prior to an application being made to the Home Office for a warrant
but the Security Service submitted his old number for inclusion on the warrant.
The warrant with this wrong number was duly signed by the Home Secretary.
The interception was suspended immediately the oversight was identified. No
communications had been intercepted and no product received. Security Service
officers have been reminded of the importance of carrying out thorough checks of
telephone numbers added to interception warrants.
2.17 The third case involved a warrant where two digits had mistakenly been
transposed when the warrant was applied for resulting in an incorrect telephone
number being intercepted. None of the product from the interception had been
transcribed and all the product has since been destroyed. Security Service officers
have been reminded to be more diligent when checking telephone numbers in
future.
5