Re: What the . . . ?
"In many circumstances this is a claim that the technology can reach inside multiple backups, even off-line backups, and magically snip out this specific piece of PII."
This is possible with a PKI solution.
Encrypt data at rest and hold the encryption keys far closer to home. after 7 years delete the keys used to encrypt that offline storage. No one can then unencrypt (NSA aside) that data & its effectively gone.