I had been saying that listening to the microphone on your phone is not practical or scalable from a marketing point of view(while 100 % possible). My recommendation though has always been removal of social media apps from your phone. #punkprivacy However looks like at least one player brags about it, so maybe they were able to implement a process that yields good ROI and proves me wrong. Please remove unnecessary apps from your phone. https://futurism.com/the-byte/facebook-partner-phones-listening-microphone #privacy