Canada: Legal Privilege For Data Security Incident Investigation Reports

Data security incident response activities usually involve the creation of sensitive communications and documents that might be subject to legal disclosure obligations unless they are protected by legal privilege. The recent U.S. District Court decision in Re Experian Data Breach Litigation provides helpful guidance for establishing legal privilege over data security incident investigation reports prepared for use in connection with litigation.

Legal Privilege

Basic Rules

There are two kinds of legal privilege under Canadian law that might be relevant to data security incident activities – "legal advice" privilege and "litigation" privilege. Each kind of privilege is different in purpose, scope and duration. Communications and documents might be protected by either or both kinds of privilege, depending on the circumstances. An organization that asserts legal privilege over a communication or document has the burden of proving that the privilege applies.

Legal advice privilege (also known as "solicitor-client" privilege) applies to confidential communications between a lawyer and client for the purpose of seeking or giving legal advice. The privilege applies whenever a client seeks legal advice from a lawyer, regardless of whether or not litigation is ongoing or anticipated. The privilege lasts unless and until it is waived by the client.

Litigation privilege (also known as "work product" privilege or "lawyer's brief" privilege) applies to communications and documents created for use in connection with ongoing or reasonably anticipated litigation. The privilege applies to communications and documents between a lawyer and client and to certain kinds of communications and documents between a lawyer and third parties. The privilege applies only if a communication or document is made for the "dominant purpose" (but not necessarily the sole purpose) of use in connection with ongoing or reasonably anticipated litigation. The privilege lasts until the relevant litigation and any closely related litigation have ended or the privilege is waived by the client.

A client may waive legal privilege. Waiver of privilege ordinarily requires the client to knowingly and voluntarily demonstrate, by words or conduct, an intention to waive privilege. Nevertheless, privilege can also be waived inadvertently or implicitly in circumstances where fairness and consistency require it.

Legal Privilege Strategy

It is prudent for an organization to establish a legal privilege strategy for its cyber risk management activities, including preparing for and responding to data security incidents, so that the organization is able to establish legal privilege, where appropriate, over communications and documents created in the course of those activities.

The importance of a legal privilege strategy is illustrated by the U.S. court decisions in Genesco Inc. v. Visa USA Inc. and Re Target Corporate Customer Data Security Breach Litigation. Each of those lawsuits related to a data incident that was subject to two separate internal investigations by separate teams – a business investigation for business purposes, and a legal investigation (directed by an external lawyer) for legal advice and litigation purposes. The plaintiffs in the lawsuits sought disclosure of the investigation reports. In each lawsuit, the court held that the report resulting from the business investigation had to be disclosed, but the report resulting from the legal investigation was protected by legal privilege and did not have to be disclosed.

More information about data security incident reporting and disclosure obligations, the basic rules for legal privilege and practical recommendations for a legal privilege strategy for cyber risk management activities may be found in BLG bulletins Cyber Risk Management – Legal Privilege Strategy – Part 1 and Cyber Risk Management – Legal Privilege Strategy – Part 2.

Experian Data Breach Litigation Decision

The decision in Re Experian Data Breach Litigation involved a consolidated class action arising out of an alleged theft of personal information of millions of T-Mobile customers and subscribers that was hosted on a server operated by Experian. After the data breach was discovered, Experian's external litigation counsel hired Mandiant, an independent forensic consultant, to conduct an analysis of the breach and prepare an expert report. Mandiant delivered the report to Experian's external litigation counsel, who then shared the report with Experian's in-house counsel. The report was used by Experian's external litigation counsel and in-house counsel to develop their legal strategy.

Experian refused to disclose Mandiant's report to the class action plaintiffs on the basis that the report was protected by work product privilege. The class action plaintiffs applied to court for an order compelling Experian to disclose Mandiant's report. The plaintiffs made four arguments, each of which was rejected by the court, as follows:

  • The plaintiffs argued that Mandiant's report was not privileged because Experian had independent business duties to investigate the data breach, and Mandiant was hired for that purpose. The court rejected that argument because the evidentiary record made it clear that Mandiant conducted the investigation and prepared the report for external litigation counsel in anticipation of litigation, even if that was not the only purpose of the report. The court noted that Mandiant's report had not been given to Experian's incident response team. The court found that Mandiant's report would have had different form and content were it not prepared for the purpose of anticipated litigation.
  • The plaintiffs argued that Mandiant's report was not privileged because Experian had previously engaged Mandiant to perform similar work regarding a data breach that occurred two years earlier, and Mandiant was just again doing work in the course of ordinary business for Experian. The court rejected that argument because Mandiant's previous work for Experian was separate from the work that Mandiant did for Experian's litigation counsel.
  • The plaintiffs argued that fairness required Mandiant's report be disclosed because Mandiant must have prepared the report based on an analysis of Experian's live servers, and it was impossible for the plaintiffs' experts to go back in time and conduct a similar analysis. The court rejected that argument because the evidence showed that Mandiant's report was based on an analysis of server images rather than access to Experian's live systems, networks or servers. The court reasoned that the plaintiffs could engage their own experts to analyze the same server images used by Mandiant, and the resulting expense and inconvenience to the plaintiffs was not sufficient to overcome legal privilege.
  • The plaintiffs argued that Experian had waived legal privilege by disclosing Mandiant's report internally and to T-Mobile. The court rejected that argument because disclosure of the report had been closely controlled by Experian's external litigation counsel and in-house legal department, and did not constitute a waiver of legal privilege. The court noted that the report was not given to Experian's incident response team or personnel working on remediation of Experian's systems affected by the data breach. The court also noted that disclosure of a redacted version of the report to T-Mobile was pursuant to a written joint defence agreement between Experian and T-Mobile, which was made because they recognized the risk of litigation arising from the data breach.

The Experian Data Breach Litigation decision illustrates some measures that a Canadian organization might take to support claims of litigation privilege over a data security incident investigation report, including:

  1. The forensic investigator should be hired by outside legal counsel expressly retained to advise the organization regarding the incident and related litigation.
  2. The organization, outside legal counsel and the forensic investigator should jointly create an accurate evidentiary record that clearly demonstrates that the investigation report is prepared primarily for legal privilege purposes, and not for ordinary business purposes.
  3. The forensic investigator's engagement should be limited to work relevant to assisting outside legal counsel to provide legal advice and prepare for litigation.
  4. The forensic investigator should deliver its report to, and communicate with, outside legal counsel only. The forensic investigator should not communicate directly with the organization's in-house legal counsel or the incident response team.
  5. The investigation report should be based on an analysis of documents and data (e.g. server images) that are preserved for subsequent disclosure in litigation.
  6. Any disclosure of the forensic investigator's report and related documents should be limited and consistent with litigation privilege purposes and carefully controlled to demonstrate confidentiality and avoid inadvertent waiver of privilege.
  7. If actual or anticipated litigation involves multiple defendants, then any disclosure of the forensic investigator's report and related documents to co-defendants should be limited (e.g. disclosure of redacted versions only) and made pursuant to an appropriate written joint defence agreement that maintains confidentiality and privilege.

It is important to note that the Experian Data Breach Litigation decision involved a claim of litigation privilege for an expert investigation report prepared for the purpose of reasonably anticipated litigation regarding a specific data security incident. The decision did not involve a claim of legal advice privilege for a technical report prepared for the purpose of legal advice regarding preventative cyber risk management activities, which would require the application of a different legal test that might not be satisfied in all circumstances.


A legal privilege strategy can help establish legal privilege over certain kinds of communications and documents created during preventative cyber risk management activities and data security incident response activities. A legal privilege strategy should be carefully planned, effectively implemented and periodically reviewed and refreshed to reflect legal advice based on guidance provided by recent court decisions. U.S. cases can be instructive for Canadian organizations, but those cases must be considered with caution because U.S. rules for legal privilege are different, in some respects, from Canadian rules.

About BLG

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

In association with
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Check to state you have read and
agree to our Terms and Conditions

Terms & Conditions and Privacy Statement (the Website) is owned and managed by Mondaq Ltd and as a user you are granted a non-exclusive, revocable license to access the Website under its terms and conditions of use. Your use of the Website constitutes your agreement to the following terms and conditions of use. Mondaq Ltd may terminate your use of the Website if you are in breach of these terms and conditions or if Mondaq Ltd decides to terminate your license of use for whatever reason.

Use of

You may use the Website but are required to register as a user if you wish to read the full text of the content and articles available (the Content). You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these terms & conditions or with the prior written consent of Mondaq Ltd. You may not use electronic or other means to extract details or information about’s content, users or contributors in order to offer them any services or products which compete directly or indirectly with Mondaq Ltd’s services and products.


Mondaq Ltd and/or its respective suppliers make no representations about the suitability of the information contained in the documents and related graphics published on this server for any purpose. All such documents and related graphics are provided "as is" without warranty of any kind. Mondaq Ltd and/or its respective suppliers hereby disclaim all warranties and conditions with regard to this information, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. In no event shall Mondaq Ltd and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of information available from this server.

The documents and related graphics published on this server could include technical inaccuracies or typographical errors. Changes are periodically added to the information herein. Mondaq Ltd and/or its respective suppliers may make improvements and/or changes in the product(s) and/or the program(s) described herein at any time.


Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:

  • To allow you to personalize the Mondaq websites you are visiting.
  • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our information providers who provide information free for your use.

Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.

If you do not want us to provide your name and email address you may opt out by clicking here .

If you do not wish to receive any future announcements of products and services offered by Mondaq by clicking here .

Information Collection and Use

We require site users to register with Mondaq (and its affiliate sites) to view the free information on the site. We also collect information from our users at several different points on the websites: this is so that we can customise the sites according to individual usage, provide 'session-aware' functionality, and ensure that content is acquired and developed appropriately. This gives us an overall picture of our user profiles, which in turn shows to our Editorial Contributors the type of person they are reaching by posting articles on Mondaq (and its affiliate sites) – meaning more free content for registered users.

We are only able to provide the material on the Mondaq (and its affiliate sites) site free to site visitors because we can pass on information about the pages that users are viewing and the personal information users provide to us (e.g. email addresses) to reputable contributing firms such as law firms who author those pages. We do not sell or rent information to anyone else other than the authors of those pages, who may change from time to time. Should you wish us not to disclose your details to any of these parties, please tick the box above or tick the box marked "Opt out of Registration Information Disclosure" on the Your Profile page. We and our author organisations may only contact you via email or other means if you allow us to do so. Users can opt out of contact when they register on the site, or send an email to with “no disclosure” in the subject heading

Mondaq News Alerts

In order to receive Mondaq News Alerts, users have to complete a separate registration form. This is a personalised service where users choose regions and topics of interest and we send it only to those users who have requested it. Users can stop receiving these Alerts by going to the Mondaq News Alerts page and deselecting all interest areas. In the same way users can amend their personal preferences to add or remove subject areas.


A cookie is a small text file written to a user’s hard drive that contains an identifying user number. The cookies do not contain any personal information about users. We use the cookie so users do not have to log in every time they use the service and the cookie will automatically expire if you do not visit the Mondaq website (or its affiliate sites) for 12 months. We also use the cookie to personalise a user's experience of the site (for example to show information specific to a user's region). As the Mondaq sites are fully personalised and cookies are essential to its core technology the site will function unpredictably with browsers that do not support cookies - or where cookies are disabled (in these circumstances we advise you to attempt to locate the information you require elsewhere on the web). However if you are concerned about the presence of a Mondaq cookie on your machine you can also choose to expire the cookie immediately (remove it) by selecting the 'Log Off' menu option as the last thing you do when you use the site.

Some of our business partners may use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies and we are not aware of any at present that do so.

Log Files

We use IP addresses to analyse trends, administer the site, track movement, and gather broad demographic information for aggregate use. IP addresses are not linked to personally identifiable information.


This web site contains links to other sites. Please be aware that Mondaq (or its affiliate sites) are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of these third party sites. This privacy statement applies solely to information collected by this Web site.

Surveys & Contests

From time-to-time our site requests information from users via surveys or contests. Participation in these surveys or contests is completely voluntary and the user therefore has a choice whether or not to disclose any information requested. Information requested may include contact information (such as name and delivery address), and demographic information (such as postcode, age level). Contact information will be used to notify the winners and award prizes. Survey information will be used for purposes of monitoring or improving the functionality of the site.


If a user elects to use our referral service for informing a friend about our site, we ask them for the friend’s name and email address. Mondaq stores this information and may contact the friend to invite them to register with Mondaq, but they will not be contacted more than once. The friend may contact Mondaq to request the removal of this information from our database.


This website takes every reasonable precaution to protect our users’ information. When users submit sensitive information via the website, your information is protected using firewalls and other security technology. If you have any questions about the security at our website, you can send an email to

Correcting/Updating Personal Information

If a user’s personally identifiable information changes (such as postcode), or if a user no longer desires our service, we will endeavour to provide a way to correct, update or remove that user’s personal data provided to us. This can usually be done at the “Your Profile” page or by sending an email to

Notification of Changes

If we decide to change our Terms & Conditions or Privacy Policy, we will post those changes on our site so our users are always aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it. If at any point we decide to use personally identifiable information in a manner different from that stated at the time it was collected, we will notify users by way of an email. Users will have a choice as to whether or not we use their information in this different manner. We will use information in accordance with the privacy policy under which the information was collected.

How to contact Mondaq

You can contact us with comments or queries at

If for some reason you believe Mondaq Ltd. has not adhered to these principles, please notify us by e-mail at and we will use commercially reasonable efforts to determine and correct the problem promptly.