The concept of “Legitimate Interest” (LI) within the GDPR framework is foundational, yet it remains one of the most misunderstood—and often misapplied—principles in data protection. After extensive discussions with Data Protection Officers (DPOs) and other privacy professionals, one fact emerges: many organizations fail to identify whose interest genuinely matters, and why that distinction is so critical.
The title—“Your Legitimate Interest Is Not Your Suppliers’”—challenges the assumption that an organization’s legitimate interest automatically extends to its third-party ecosystem. It does not.
The Core Question: Who Owns the Legitimate Interest?
Legitimate interest, one of the six lawful bases for processing personal data under GDPR (General Data Protection Regulation), is not a blanket authorization for data processing. Under the GDPR, it allows a data controller to process personal data only when doing so serves a genuine interest that does not override the fundamental rights and freedoms of the data subject. Understanding who holds this legitimate interest, and on whose behalf it is asserted, is essential for determining whether processing is lawful.
This issue becomes especially relevant when third parties enter the picture. While your organization may have a direct, established relationship with your users, a third-party supplier—such as an ad-tech vendor or analytics platform—typically does not. Without a direct relationship, these suppliers cannot rely on your legitimate interest as their own legal basis for data processing.
In fact, when third parties access a user’s terminal equipment, by placing or reading cookies, using device fingerprints, or deploying similar tracking technologies, they trigger additional obligations under the ePrivacy Directive. Article 5(3) of the ePrivacy Directive explicitly requires user consent before any such third-party terminal access can occur, except in very limited circumstances. This is not a mere technicality; it’s a legal mandate that supersedes any assumption of a shared legitimate interest. If a third party attempts to leverage your legitimate interest without meeting these consent requirements, they risk non-compliance and the erosion of user trust.
In short, legitimate interest belongs to the data controller with the direct user relationship. Once you involve external parties, consent becomes the legally required standard. Without it, the entire data processing chain rests on shaky ground.
Misusing Legitimate Interest: More Than a Compliance Problem
Extending legitimate interest to cover third-party suppliers isn’t just a legal misstep—it reflects a deeper cultural issue. This goes beyond the GDPR or ePrivacy Directive. It signals a disconnect from the emerging trust economy, where respecting user data and ensuring genuine transparency are paramount.
Regulators are clear: legitimate interest cannot conceal insufficient transparency. The European Data Protection Board’s (EDPB) Guidelines 2/2023, for example, stress that legitimate interest cannot justify third-party tracking—such as cookies or behavioral profiling—without explicit user agreement.
This misapplication doesn’t just invite regulatory fines; it also damages trust. Customers who feel their data has been misused become reputational liabilities. In today’s digital landscape, trust isn’t earned through mere claims of compliance—it’s earned through consistent, demonstrable respect for user autonomy.
A Call for Accountability: Rethinking Your Privacy Framework
It’s time to stop viewing legitimate interest as a convenient loophole or fallback. Instead, reimagine your data practices through the lens of accountability:
- Redefine Transparency: Move beyond minimal legal disclosures. Communicate clearly so that users genuinely understand who is accessing their data and why.
- Challenge Assumptions: If your legitimate interest argument depends on suppliers, ask whether it truly aligns with user rights. If not, consent—not LI—must guide your decisions.
- Embed Privacy by Design: Prioritize privacy from the start. By building privacy safeguards into operations, legitimate interest will only be invoked where it’s appropriate and defensible.
Where Do We Go From Here?
The future of privacy compliance lies in acknowledging that the power dynamic has changed. Users demand more control over their data, and regulators are prepared to enforce this expectation. Properly applied, legitimate interest remains a valuable tool. Misapplied, it’s a liability.
The question is no longer just whether your legitimate interest is valid, but whether it can withstand regulatory and public scrutiny. If you’re leaning on suppliers to justify their processing under your legitimate interest, you’re already on unstable ground.
As we move into this privacy-first era, let’s view the GDPR and the ePrivacy Directive not as obstacles, but as catalysts—opportunities to redefine trust, transparency, and accountability in how we handle data.
Ronni K. Gothard Christiansen // VikingTechGuy
Creator, AesirX.io
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