There could be way more hidden tech/features people are not aware of that are utilized by government agents to aid in criminal investigations. It's just better to use open-source stuff when doing nothing immoral that needs to be privacy protected
How am I supposed to use Open Source stuff in my case. Why involve the immoral part. I only asked if there was proof of such thing.
There are some Open Source Smart phones out there. But they lack a lot of functionality and have big issues. Some of them like Librem 5 are not even released yet. Anyway. I do not know if their phone camera is Open Source too. I am curious if they have ever been caught stamping watermarks on photos or videos in some ways besides EXIF.