I took a few forensics lessons in the past and it was always trained that magnetic disks take several passes of wipes to truly make your data unrecoverable. I believed this particular for years and always recommended a full 3-5 pass DoD wipe. Yesterday I was reading some vendor paperwork that states that modern hard disk drives only needed a single pass now to accomplish this. I had to go searching and sure enough, there are references out there stating this in the last handful of years, including NIST. I guess I wanted to hear this from somebody in the field to help me confirm this. Is this valid? We didn' t think magnetic mass media changed that much in the last handful of years. Thoughts?