Claiming the “mosaic effect” requires showing that specific personal information would be disclosed

Complaint: Transport Canada refused to release aircraft registration numbers, claiming they were personal information under subsection 19(1).

Investigation: Transport Canada maintained that by cross-referencing these numbers with information on the publicly available Canadian Civil Aviation Register website, it would be possible to discern the names and addresses of the owners of registered aircraft involved in air occurrences.

Outcome: As a result of the investigation, Transport Canada released the records in full, claiming it was doing so using its discretion to release personal information in the public interest under subparagraph 8(2)(m)(i) of the Privacy Act. However, the Information Commissioner found that the information did not qualify as personal information and should not have been withheld under subsection 19(1) in the first place.

Information Commissioner’s position

  • To withhold records under subsection 19(1) in this instance, Transport Canada would have had to demonstrate that releasing various types of seemingly unrelated information would paint a larger picture that would disclose specific personal information (known as the “mosaic effect”).
  • Transport Canada could not do so in this case. At most, someone might have been able discern the identity of the owners of aircraft involved in air occurrences, but not whether these owners were personally involved.
  • In its decision in Canada (Information Commissioner) v. Canada (Canadian Transportation Accident Investigation and Safety Board), 2006 FCA 157, the Federal Court of Appeal said that the possibility that information might be cross-referenced with other sources does not render otherwise “non-personal” information “personal.”
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