This exact situation has been discussed ad nausea before. Siri, FB, Goggle do not listen and market to you based on your conversations. But they will based on proximity. I have a "private" conversation with my doctor about a procedure and I don't use the internet reference it. But, I might tell a spouse who looks it up and since I am on the same ISP, I will start getting ads. Or I'm in proximity to a friend who then leaves and immediately looks it up. Since the devices have GPS, it knows the two people were in close proximity and then the ads come. Everything we are doing is being tracked. Siri et al. does not need to spy on you to get the data.