We know for a fact that some phones are secretly listening and uploading stuff.[...

We know for a fact that some phones are secretly listening and uploading stuff.[1-4] It's done by spying apps. How do we know? Because there are tons of researchers reverse engineering stuff trying to find this stuff. These researchers are extremely hungry for a big find, for some big publicity. They're searching very hard to find a big player doing it, but none of the big players are doing it, so they only make small headlines with the small players they find.