5.14.Stoter heeft bij zijn onderzoek van de HAR files de volgende cookies aangetroffen: MUID, MSPTC, CLID, de bcookie en de li_gc cookie. Dat de eerste drie tracking cookies zijn, is al geoordeeld in het vonnis van 7 juni 2024. Dat van de bcookie op dat moment niet aannemelijk was dat het een cookie was waarvoor toestemming vereist was, betekent niet dat die cookie voor altijd uitgezonderd is van het gebod. Op grond van het rapport van Stoter is nu wel aannemelijk geworden dat ook de bcookie een tracking cookie is, gelet op de karakteristieken ervan. Stoter heeft daarover het volgende in zijn rapport opgenomen:
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LinkedIn states that the cookie and li_gc cookies are functional cookies and therefore do not require consent to be stored and accessed on users’ devices. The bcookie’s role is stated as being to assist LinkedIn in recognising its members’ browsers on its platform, and is therefore an aid to preventing fraudulent use of its platform. The li_gc’s role is not related to security but is stated as being to provide a persistent record of guests’ consent to non-essential cookies, with “guests” presumably meaning visitors to the linkedin.com domain.
There are a number of factors that raise doubt as to these claims. The way that these cookies are configured, they enable LinkedIn to conduct tracking. The principal three factors that are inconsistent with the stated purposes are: (1) these cookies are being placed on third party websites, and (2) the cookies have unnecessarily long expirations, and (3) that they are read and set through network calls to LinkedIn’s ad server.
Placement on third party websites
Perhaps the most striking inconsistency with the stated purposes of these cookies is that both the bcookie and li_gc cookies are being set and read across a vast range of third-party websites that are entirely unrelated to the LinkedIn platform. Such behaviour aligns more closely with practices associated with tracking consumers across websites for profiling and advertising purposes, rather than the purposes claimed by LinkedIn.
If the bcookie is intended to enable LinkedIn to recognize its members and detect abuse “on the platform,” this use may be understandable on the LinkedIn platform but it is difficult to justify why this cookie is also being set and read on third-party websites that are not part of the LinkedIn platform. Not only is the cookie being set for all visitors to these websites—many of whom are not LinkedIn members—but it is also being read by LinkedIn whenever users visit these unrelated websites. This enables much broader use than abuse detection.
Similarly, if the li_gc cookie’s purpose is to “store consent of guests regarding the use of cookies for non-essential purposes,” it is equally challenging to understand why this cookie is being set and read on third-party websites. This cookie is being deployed for all visitors to these websites, not just LinkedIn "guests," representing a significant overreach beyond its stated purpose. Furthermore, it is unclear why LinkedIn would need to set and read a consent-management cookie on websites that LinkedIn neither owns nor controls, suggesting a lack of transparency and potential misuse.
Finally, the use of these cookies on third-party sites cannot be reconciled as lawful under the guise of functional cookies. For cookies to be considered functional, they must serve a purpose directly related to the operation or functionality of the specific website where they are deployed. In this case, the setting and reading of these cookies are being carried out on websites where they serve no discernible function, making it difficult to identify a lawful basis for such activity under European or Dutch law. These practices appear to contravene legal requirements for transparency, necessity, and proportionality.
Long expiries
Both the bcookie and li_gc cookies are set with unusually long expiries—12 months and six
months, respectively—raising significant questions about whether such durations are necessary for their stated purposes.
For the majority of LinkedIn users who access the platform regularly, a 6- or 12-month expiry is excessive. A 30-day expiry would likely suffice to recognize returning users and store consent preferences, while still allowing for normal periods of inactivity. Each time users visit LinkedIn, these cookies could be reset, providing an entirely adequate means of recognizing users and managing consent without requiring such long-lasting identifiers.
For fraud prevention, a 12-month expiry for the bcookie is particularly questionable. Industry norms for fraud detection cookies typically involve short lifespans of days or weeks, as fraud risks are most acute during or immediately following a session. A shorter expiry would reduce privacy risks by limiting the potential for persistent tracking across time and third-party sites while still serving LinkedIn’s stated purpose. Given that most users interact with LinkedIn regularly, re-setting the cookies during these interactions would achieve the necessary functionality without relying on an extended lifespan.
The long expiry periods of these cookies—especially when they are set and read across third-party sites—strongly suggest, and at least enable, a purpose beyond what has been stated. Expiries of 6 to 12 months are highly advantageous for tracking and audience building, as they enable persistent identification of users across multiple sessions and websites over extended periods. This would allow LinkedIn to correlate a user’s activity on third-party sites with their LinkedIn profile, build detailed behavioural profiles, and track advertising effectiveness. Such prolonged tracking ensures continuity even if users clear their cookies infrequently, facilitating long-term audience segmentation, retargeting, and data collection.
In conclusion, the extended lifespans of the bcookie and li_gc are neither necessary nor
proportionate to their stated purposes. These practices contravene the principles of data
minimization and proportionality under GDPR, as they retain data for far longer than required for their intended use and create undue risks to user privacy.
Connecting to an ad server
It is noteworthy that the setting and reading of these cookies is performed through network calls to px.ads. linkedin.com , which LinkedIn has acknowledged as their advertising server. While it may be intuitive for the li_gc cookie to interact with an ad server if its purpose is related to managing consent for advertising, it is surprising that a security-focused cookie such as the bcookie would be set and read via an ad server rather than through LinkedIn’s dedicated security infrastructure. Apparently, the bcookie is related to the advertising activities of LinkedIn.
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