357
Apple’s Photo Bug Exposes the Myth of ‘Deleted’
(www.wired.com)
This is a most excellent place for technology news and articles.
This is how delete works on all disks and filesystems, SSD too. It just is marked as free in the fs tree. "Real" delete is called secure delete and is slow.
Rewriting bits to 1s or 0s is very slow especially in mechanical drives and is hard on equipment. Even SSDs have a rated max writes, if we rewrite all data every delete it will decrease the lifespan of hardware.
This is why is assumed they mark them to overwrite. Google knows a lot about what makes drives last longer, and OS and drive firmware makers have known for decades too.
Every so often I scrub the free space of my drives to make sure I'm not retaining exploitable garbage data. Easier to do that once every week or so than to secure delete every file.