Well we are currently having a heated debate at work with my team around hard disk scrubbing.
My team members all of who are still rather green in the IT industry are taking the perspective that all drives from servers need to be smashed with a hammer and thrown in the
My perspective after working inside one of the large banks for many years, reviewing data recovery techniques and speaking to computer forensics people is that you can erase a drive so data cannot be recovered, in fact he pointed out you are more likely to be able to get data off a smashed drive than one that has had multiple scrubs (every block rewritten on the drive). Apparently after one rewrite you need to be removing platters and getting out a microscope to inspect each of the bits on the drive for its residual state.
US DOD standards up until 2007 specified that seven rewrites was sufficient, they have now changed their position to requiring a degauss which as well as erasing the drive effectively renders it useless. The perspective here is they are concerned with well funded foreign governments getting their data.
In this era of corporate responsibility we are all told to be green and not throw out e-waste in the bin. In our organisation we donate old gear to a charitable trust who specialises in its redeployment. At the moment we are looking at letting them have old servers, however possibly with no disks. Apparently this is not an issue as disks are cheap and not a problem to replace, this may be the case for desktops but as you are all aware servers use mainly more expensive less readily available SCSI drives (and more recently SAS).
So how about a hypothetical scenario. Lets say we have a drive that had some data, this drive has been erased to the old DOD (DoD 5220.22-M) standard prior to Jun 07 where the drive has been rewritten seven times. This data if recovered is worth over a million dollars. Is there anyone out there who has the resources to attempt a successful recovery. BTW lets make the data set around 2GB in size, a database so a partial recovery still may be useful.