olemus
jääkandmed magnetkandjal
= the retention of erased data on a magnetic medium

ülevaateid
https://en.wikipedia.org/wiki/Data_remanence
http://www.wisegeek.com/what-is-data-remanence.htm
https://fas.org/irp/nsa/rainbow/tg025-2.htm
http://all.net/books/iw/iwarstuff/www.fish.com/security/secure_del.html

vt ka
- demagneetimine