# O3.26 Implement strict controls to enforce purpose limitation and restrict secondary data use

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{% tab title="Principle" %}
[O3: Ensure data privacy by design](../principles/operational-principles/o3-ensure-data-privacy-by-design)
{% endtab %}

{% tab title="Risk" %}
[RS1 Privacy vulnerability](../risks/risks-to-safety), [SV1 Digital distrust](../risks/risks-to-structural-vulnerabilities)
{% endtab %}

{% tab title="Lifecycle Stage" %}
[L2: Strategy and Design](../life-cycle-stages)
{% endtab %}
{% endtabs %}

## Practices

> Design DPI systems to enforce data processing strictly according to the predefined purposes.
>
> Design tools that require explicit user consent for any data use beyond the initially stated purpose.

## Resources

<table data-view="cards"><thead><tr><th></th><th></th><th></th></tr></thead><tbody><tr><td>Case Studies</td><td></td><td></td></tr><tr><td>References</td><td></td><td></td></tr><tr><td></td><td></td><td></td></tr></tbody></table>
