That's correct. Apps must request access to the microphone, and iOS shows an indicator while the app is recording. This is pure confirmation bias. If someone t

That's correct. Apps must request access to the microphone, and iOS shows an indicator while the app is recording. This is pure confirmation bias. If someone tests this and doesn't get a relevant ad from Facebook, they won't upload a video or tell their friends. Note that even in this confirming case, it took two days before the guy saw a cat food ad. We don't know how many other ads he scrolled by before that one.