Veritas makes it as easy as flipping a flag to kick the tape dump into DES with a static key, which would make the cracking effort outweigh the value of recovery. I believe now you can also kick on 128-AES which while theoretically breakable some day in the future given the right hooks, is well beyond reasonable cost justification for the data. A question becomes how much it slows down writing the tapes.

These probably were not backups, though. They were sent TO Experian. Experian is a data warehouse for financial data, not a backup storage facility. Still leaves open the question of why no crypto.

But there are bigger questions -- like what kind of screwy system makes this low-threshold data the keys to the kingdom.