I saw an IT "consultant" demonstrate how to neuter a drive (before selling or donating the system or after killing your wife) on TV.

She took a 1/4" drill and made several holes in the circuit board on the bottom of the drive.

I called her, and suggested that the board could be replaced in under two minutes and, with the disk platters intact, the whole of the data would be accessible.

She replied, "Well, most thieves wouldn't think of that."

No, but your business rival might.