Where is this "£1m waiting for you" you're talking about? If you are claiming that it is impossible to read the old data when a hard drive has new data written over it in the same sector, you're wrong. There are research papers where they succeeded in reading data that had been overwritten 4 or 5 times.
Maybe it is more difficult with modern drives that are so much denser that back in the 90s when this was being done. MIL SPEC erasure did not come about to protect against a theoretical attack.
Biting the hand that feeds IT
