The shred command and security?

[Bruno Wolff III]

On Wed, Dec 05, 2007 at 10:58:09 +0000,
  Mike C <mike.cloaked at gmail.com> wrote:
> In the event that you want to give a Fedora machine to a friend but want to
> remove sensitive files first, an obvious tool is the shred command.

An easy way to do this is to boot with a livecd and the copy /dev/zero to
the raw disk devices (or use a destructive write test with badblocks). Once
that is complete do a fresh install.

Recovering data from reallocated (by the disk drive) sectors (if you even
have any) would be difficult and would not normally be much data. Recovering
data by looking at the platter with say an electron microscope and trying
to recover traces of old data isn't going to be economically feasible.