> Not really. 99% of the time it's someone claiming that it happens.
It’s never packet captures, reverse engineering of the app, or one of the tens of thousands of employees working for these companies blowing the whistle.
Nobody can even show that their phone app is using background CPU when they talk, utilizing the microphone, or sending packets from that app. All of which are in reach for anyone with Android and some basic skills.
It’s always an anecdote about someone who said something out loud and then saw ad for it later. That’s it. That’s the entire basis for the conspiracy. Yet it persists.
It’s a very good litmus test for people who don’t understand technology as well as they claim to.