99% of indigenous people were lactose intolerant. They would’ve stopped drinking milk very quickly as you can get the upset stomach drinking milk.

You sure about that? because if it’s Google, that particular method of doing this would be easily discovered.

Also, the scary part isn’t that they could do this by listening to your phone, the scary part is that they DON’T need to listen to your phone to do exactly that. Much easier to identify multiple devices coming from the same network (both physical and social), and then figuring out query interests, and then send ads down the same pipelines.