Remnant data is data that can be recovered from magnetic media after new information has been written to that media. Although remnant data has been recovered from magnetic tapes and floppy disks, there is no credible report that has been published in the open literature that remnant data can be recovered from modern hard drives.
References
- Detection of Digital Information From Erased Magnetic Discs, by Venugopal V. Veeravalli , Master's Thesis, Carnegie Mellon University, 1987