Is the copied file going to a usb? Is the usb fake? Otherwise I’m pretty sure your source is bad. Probably the disk sector if you’re sure the file was at some point complete.
Something like btrfs probably does block cloning or similar so a copy to the same disk probably just points at the same disk blocks as the original.
Bring free on cloudflare makes it widely adopted quickly likely.
It’s also going to break all the firewalls at work which will no longer be able to do dns and http filtering based on set categories like phishing, malware, gore, and porn. I wish I didn’t need to block these things, but users can’t be trusted and not everyone is happy seeing porn and gore on their co-workers screens!
The malware and other malicious site blocking though is me. At every turn users will click the google prompted ad sites, just like the keepass one this week.
Anyway all that’s likely to not work now! I guess all that’s left is to break encryption by adding true mitm with installing certificates on everyone’s machines and making it a proxy. Something I was loathe to do.