edit: I was wrong, they were pretty up front with users about the purpose of recording (https://www.techrepublic.com/article/how-one-spanish-soccer-...)

From the article: "Despite this, users were not explicitly informed of the intended use of the microphone and geolocation permissions, which is central to the decision by AEPD to levy fines against LaLiga."

Sounds like they were spying while using microphone permissions, which is what the discussion is about.

And they prompted people to opt-in (with somewhat leading language) into this system to search for unauthorized playback. So there was no need to "discover" that the app did that, because the app literally said it had a system to do so. There is a range between "secretly" (= would need research attention to discover it happens) and "done correctly legally".

Thanks for this! Found another article where this is better explained: https://www.techrepublic.com/article/how-one-spanish-soccer-...