I've got ads and tracking pretty tamped down on my own devices, but it's honestly terrifying how often when I hang out with friends who have non-FOSS phones or Windows running in the room that Amazon is later trying to sell me the topics of the conversations we were having. And it's really hard to have a conversation with someone who isn't as sensitive to this, to tell them that their devices and software are compromising my privacy, and to get them to understand that as the consent issue it truly is.