A salutary lesson not to trust spreadsheets

Spreadsheets do funny things to data. Firstly, they do a lot of formatting and sometimes that messes up your numbers. Secondly, they behave like programs but don’t get any of the rigorous checking that we would expect of a chunk of C++ code or the like. Here, should you still need to be told this, is a fine example of how you can end up in deep trouble without even knowing it’s coming. In 2010 it seems the organisation most Brits call MI5 tapped 134 phones by mistake. Oops! The reason was formatting in a spreadsheet:

In 2010 the Security Service reported 1061 errors to my office which can be
split into two categories.  First, subscriber data was acquired in relation to 134 incorrect telephone numbers.  These errors were caused by a formatting fault on an electronic spreadsheet which altered the last three digits of each of the telephone numbers to ‘000’.  These unfortunate errors were identified by the Security Service and duly reported, which is again a positive indication that public authorities are self auditing and identifying any conduct which constitutes non-compliance.  A degree of unintended collateral intrusion occurred in relation to these 134 requests as the subscriber data acquired had no connection or relevance to any investigation or operation being undertaken by the Security Service.  In line with paragraph 6.21 of the Code of Practice the Security Service has now destroyed this material.  The technical fault on the spreadsheet has been rectified and all requests are also now checked manually before being sent to the CSPs which will reduce the potential for recurrence of such errors.

– from the 2010 annual report of the Interception of Communications Commissioner.

Remarkable stuff. Thanks to EuSpRIG for cataloguing this and many other horror stories.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s