Carla Feakins at Lewis Silkin discusses Argus Media Ltd vs. Halim and the fact that the Court found that as long as an email trawl is reasonable and proportionate, it will not infringe an employee's privacy rights.  This fact of this case is related to suspicious actions carried out by the employee whilst serving their notice period.  This is just one example of when a forensic analysis of emails or other digital devices can be revealing.

But how do you assess whether it is reasonable or proportionate?  I cannot comment on this from a legal perspective, not being a lawyer, but it seems to me that there needs to be some concern or suspicion required to trigger this sort of analysis.

What I can comment on is how technology can be used to help protect any unnecessary infringements on privacy by targeting specific data sets.  These include:

  • Keyword searching: the obvious technique to use to help focus on documents that may be of interest to an investigation. These can also be used in the reverse to identify potentially private data if specific terms can be defined;
  • Date range filtering: another obvious technique to restrict the documents being reviewed to those within a specific, targeted date range related to the suspicions;
  • Auto-redaction: this allows for a subset of private terms to be automatically redacted from a data set and thus prevents them being viewed by whomever is reviewing the documents, although the protection is limited to specific terms;
  • Anonymisation / Pseudo-Anonymisation: allows for specific information within the data set to be replaced by one or more pseudonyms, although, again, the protection is limited to specific terms; and
  • Technology Assisted Review / Continuous Active Learning: essentially a form of machine learning where the entire population of documents can be prioritised based on a review of a small sub-set, thus reducing the number of irrelevant and potentially private documents that are reviewed.

None of the above is a silver-bullet that will solve the problem in its entirety, nor are they normally used in isolation, but rather a combination of many of the above are used in parallel.  This then provides a technical toolkit that can be used to meet the legal requirements, however they are defined, to undertake the work in a reasonable and proportionate manner.