Canada: MAC And IP Addresses: Personal Information?

Last Updated: July 26 2012
Article by Timothy Banks

A minor kerfuffle broke out at a recent (May 30, 2012) U.S. Federal Trade Commission workshop, "In Short: Advertising and Privacy Disclosures in a Digital World."  During a discussion of a privacy and advertising on mobile platforms, Sara Kloek, Director of Outreach for the Association for Competitive Technology, stated that a MAC address was information about a device and not personal information. Pam Dixon, founder and executive director of the World Privacy Forum, was quick to snap back stating that a MAC address was personal information.

Who is right?  Why is it that we are still debating this fundamental issue?  And is the answer different for IP addresses?  This post is a bit longer than most here on but I'll try to unpack these issues in the context of Canadian privacy laws and principles.

What's a MAC address?

A Media Access Control address is an alpha-numeric number that is assigned to a hardware device that connects to a computer network. In simple terms, a MAC address is part of the addressing system that will allow one device to route packets of information to another device.  I'm a lawyer and not a technologist but I think it is fair to say that the MAC address for my smart phone will, for example, be visible to a retailer operating a wireless network when I come within range of that network.  The MAC address will be used by that wireless network when I connect to access the Internet or network services of that retailer.

Each device has a unique MAC address (leaving aside counterfeiting and spoofing).  Therefore, the MAC address for the device may be harnessed as a unique identifier for more than network functionality when it is visible or when an application installed on my device inspects and relays the MAC address. So, a MAC address could be a potential gateway to collecting information on the activities of users of that device when connected to the Internet.  (I wrote "users" deliberately because although there is probably only one user of my smart-phone, the same may or may not be true for any family's laptop and other devices.)

A MAC address can also be used as a tool in tracking the movements of the device.  For example, Wi-Fi access points will have a MAC address that can be mapped geographically.  When a device (such as a smart-phone, tablet or laptop) interacts with a Wi-Fi network, the MAC address for that device will also be visible, thereby permitting anyone interacting with the device to determine the location of the device, provided that that person (a) knows the location of the Wi-Fi access point and (b) can see the MAC addresses of the access point and the device.

What's an IP address?

An Internet Protocol address is a numerical label that is assigned to an addressable connection to the Internet. The IP address is also part of the addressing system (at a higher level than the MAC address).  It is used in routing packets of information over the Internet.  Again, I am not a technologist but my understanding is that, for most consumers, the IP address is probably not static or permanently assigned to their device.  Instead, the IP address will be dynamic.  The consumer's Internet service provider will assign an IP address for a period of time, which might be reassigned to someone else after the consumer disconnects. However, an Internet service provider is able to correlate the IP address at a specific date and time to a subscriber to whom it is providing Internet service access, assuming it retains that information.

The issue gets a bit tricky when a wireless network router is involved.  Take my home wireless network as an example.  The router gateway to the Internet service provider may be assigned an IP address by the Internet service provider.  That IP address may be changed from time to time. Each device connected to the home network will each have an individual IP address internally to the network system.

What's personal information?

Personal information is defined in Canadian private sector privacy legislation as information about an identifiable individual.  There are some exceptions, but that is the basic definition.

Although reasonable people can debate the point, one justification of privacy legislation – whether applicable to the private sector or the public sector – is that it is necessary to protect individuals from unreasonable surveillance.  Indeed, there was a telling exchange at the FCC workshop mentioned at the outset of this post, when Pam Dixon said that the MAC address was personal information since, after all, it could be correlated to an individual and be subject to a subpoena.

Unreasonable surveillance may be viewed as inimical to personal liberty and potentially used as a tool of manipulation or, in its worst form, oppression.  Even when an organization engages in surveillance for public good or passively without seeking to manipulate, some view this as a significant intrusion since the information obtained through that surveillance may be conscripted by the power of the state for other purposes.

The problem that privacy advocates face is that the gateway concept of "personal information"as currently drafted in Canadian privacy legislation is probably too amorphous in many cases to constrain systematic surveillance in a coherent way.

Thus, in a recent appellate case last year, the Alberta Court of Appeal concluded  that in order for information to be about an "identifiable individual", the person must be identifiable, the information must have a precise connection to an individual.  In order to be "personal" the information must be about the individual–that is, directly related to the individual.  Information did not become personal information simply by being associated indirectly with an individual through ownership.  Without that limit, "virtually every object or property is connected in some way with an individual" and would become personal information.

So, a driver's licence is personal information in Alberta but a licence plate is not.  The driver's licence is uniquely connected to a person. Indeed, the driver's licence card functions in Canada as an identification card – that is, government issued identification.  On the other hand, in Alberta, at least, a licence plate is connected to the vehicle and only linked through a database to an individual. Reasonable people can debate the Alberta decision and whether other appellate courts should follow when the issue arises.

So what's the answer?

In one sense, the answer is easy.  The Office of the Privacy Commissioner of Canada considers that an IP address may constitute personal information if the IP address is associated with or linked to an

identifiable individual.

Similarly, in a commendable and comprehensive study of the issues, the Information and Privacy Commissioner of Ontario and Kim Cameron argue that MAC addresses, as unique identifiers, may be linked to individuals and, therefore, may constitute personal information.

The precautionary principle suggests that organizations should treat MAC and IP addresses as personal information.  However, in many (most?) cases, MAC and IP addresses may not be directly linked to individuals.  An Internet service provider will be able to associate the IP address to a home or business account but not (at least in the ordinary course) to any particular person using a device linked to the Internet, particularly if we are talking about my access to the Internet through a WiFi system at a coffee shop.  A MAC address does not disclose who actually has possession of the device.  However, there is a greater probability of correlation between the owner of the device and the MAC address than there is of an IP address and an individual.

So we are back to where we always are with personal information.  A MAC address or an IP address information is rarely going to be in and of itself information about an identifiable individual in the sense of having a precise connection and being directly related to an identifiable individual.  It is the context of how the MAC address or IP address is combined with other information (or could be reasonably be combined with other information) that has privacy advocates concerned.  In each case, of course, if you knew and combined enough on-line and off-line information you might have enough data to make a highly probably guess about who was doing what and where.  But the same could be said about a licence plate number.

So who was correct (from a Canadian perspective) at the FTC workshop?  Both.  In and of itself, a MAC address (and an IP address) are likely not personal information but they are rich gateways to the collection and the accumulation of data points that can transform them into personal information if privacy (anti-surveillance) measures are not built into the technologies using these addresses.  Ultimately, what is personal information is fundamentally determined by context.  The debate will continue.

For more information, visit our Data Governance Law blog at

About Fraser Milner Casgrain LLP (FMC)

FMC is one of Canada's leading business and litigation law firms with more than 500 lawyers in six full-service offices located in the country's key business centres. We focus on providing outstanding service and value to our clients, and we strive to excel as a workplace of choice for our people. Regardless of where you choose to do business in Canada, our strong team of professionals possess knowledge and expertise on regional, national and cross-border matters. FMC's well-earned reputation for consistently delivering the highest quality legal services and counsel to our clients is complemented by an ongoing commitment to diversity and inclusion to broaden our insight and perspective on our clients' needs. Visit:

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
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 you may opt out by clicking here

    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.

    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.


    From time to time Mondaq may send you emails promoting Mondaq services including new services. You may opt out of receiving such emails by clicking below.

    *** If you do not wish to receive any future announcements of services offered by Mondaq you may opt out by clicking here .


    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.

    By clicking Register you state you have read and agree to our Terms and Conditions