EU advertising libraries mandate archiving, reach data, and transparency under the DSA, enabling fraud and influence detection even after ads stop running. In contrast, most US online ads disappear without trace, making large-scale manipulation effectively invisible.

Ad fraud thrives where ad systems lack transparency, allowing platforms to profit while users and businesses bear the harm.

Strong ad transparency, as required by the DSA, is essential to stop scams in real time, trace who was targeted, and hold platforms accountable.