I"ve had to live with these requirements
for the past three months. My initial project was to merge DSS with the corporate security standards, keeping the stricter of the two (Yes, some of the internal requirements are much stricter than PCI). The questions get quite interesting when you start to apply them to a mixed environment of mainframe, Unix, Linux, and Windows.
The questions about residual data on these drives is something that had been given only cursory investigation. PCI has force us to re-examine this issue.
The cost of destroying the drives exceeds the penalty for non-compliance. The cost to brand would be huge if there was a privacy leak.
Should we be destroying the drives? Maybe. As with every security issue it comes down to cost vs risk. My job is to report on risks and possible solutions. I do like Crazy's suggestion about setting up a workstation to scrub the disks before EMC takes them - if we are contractually allowed to remove the drives. I will also recommend that the EMC contract be reviewed to see if they are required to scrub the drives prior to reuse, and if they are not, see if we have the necessary language added.
And fwiw, we have other data storage vendors also. I just happened to start the discussion with the EMC group. It will only get uglier!
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. (Herm Albright)