Facebook and other apps secretly listen to your conversations through your phone's microphone to target ads.
Users observe targeted ads appearing shortly after discussing topics not visited online, inferring microphone surveillance; however, this confuses correlation with causation. Continuous background audio recording at scale, billions of devices capturing, processing, and indexing conversations, would create detectable power drain, network traffic, and heat signatures impossible to hide. Audio processing and storage costs would dwarf advertising revenue gains. Instead, Facebook's actual surveillance is behavioural: tracking clicks, search history, location, purchase patterns, and third-party data purchases via data brokers, then using algorithmic targeting so accurate users assume eavesdropping occurred. Confirmation bias amplifies this; users remember coincidental ads (the ones that match recent conversations) while forgetting thousands of irrelevant ones. In rare cases, apps requested microphone permissions explicitly; users granted them without reading, creating the impression of covert access. Legitimate concern exists around privacy and data collection, Facebook's practices are ethically troubling, but the microphone listening claim has been systematically investigated and debunked by security researchers, with no credible evidence of large-scale surveillance.