There is still the metadata the operating system stores with the file, even when the file is 1:1 identical. When you use Apple AirDrop to send a file to a frien

There is still the metadata the operating system stores with the file, even when the file is 1:1 identical. When you use Apple AirDrop to send a file to a friend the OS remembers who sent the file to your friend. Now if the police ever looks at your friend‘s computer they can see who this file came from. Or your friend saves it onto a usb formatted with an Apple File System the metadata is still preserved.