Wiping hard drives to stop wasting money
I saw this post today and can't believe this myth is still out there. Here's the scoop, go ask an IT person "How many times do I have to wipe a drive to completely erase it?" You will hear many answers and the most popular will likely be 3 times, 7 times, it can never be erased. Let's clear it up. If you make one pass correctly your mission is accomplished. This is how magnetic media works, feel free to test it yourself with the forensic/data recovery tool of choice. How does wasting money come into play?
I was once part of a project testing multiple web proxy vendors. A work policy stated that hard drives could not be returned to vendors and all drives had to be degaussed then shredded. This was for non-classified material that would be tough to even call sensitive. One vendor was set to charge around 16k for the drives in their product. In order to avoid this charge I began asking if there was a waiver process, how it worked, and if the policy was in-house or from a more "legal" entity. Sure enough, there was a waiver process. I filled out the (un) necessary forms and also attempted to explain why this may not be required in the future in order to save my company and the vendor money. No amount of demonstration or discussion seemed to convince people that seven passes, degaussing, and shredding were the only way to maybe prevent our data from falling into the hands of the empire. This was a two-week process with regular chastisement received by me for even attempting to return a drive. At the culmination of the project I erased the drives manually using dd and then handed them to our other forensic examiner to ensure he could not retrieve data. The data was gone, the drives returned and we managed to save thousands of dollars. As I gave the final status report one of the managers stated "We probably could have saved $16,000 if we had just followed the policy." Feeling offended by that I retorted "If the policy is technically inaccurate or wrong, we should fix the policy because it makes us look stupid." Not my most humble moment.
As far as I know that company continues to destroy drives in the name of security that could be recycled, reused, or returned . This effort likely costs millions of dollars annually and provides landfills with many tiny shards of metal that will never break down. Policies are good things when they are accurate.