On the assertion that Spanish radio listeners are primarily illegal immigrants, especially if it is to be used to justify mass surveillance.

I would also note that Nielsen rating are based on an incredibly small number of Nielsen listeners. Their system might be good enough for advertising, but not for dragnet surveillance.

Look, I get that if you are worried about illegal immigration, then using FR at Latin concerts has a rough logic. My point is that targeting ethnic groups for mass surveillance is not good for anyone.

(Note: I see where you said the government should probably not do that, but the rest of your post seemed to support the practice.)