Journaling filesystems (such as Ext3 or ReiserFS) are now being used by
       default  by  most Linux distributions.  No secure deletion program that
       does filesystem-level calls can sanitize  files  on  such  filesystems,
       because  sensitive  data  and  metadata  can be written to the journal,
       which cannot be readily accessed.  Per-file secure deletion  is  better
       implemented in the operating system.

       Encrypting  a  whole  partition  with cryptoloop, for example, does not
       help very much either, since there is a single key for all  the  parti‐
       tion.

       Therefore  wipe is best used to sanitize a harddisk before giving it to
       untrusted parties (i.e. sending your laptop for repair, or selling your
       disk).   Wiping  size issues have been hopefully fixed (I apologize for
       the long delay).

       Be aware that harddisks are quite intelligent beasts those days.   They
       transparently  remap  defective  blocks.   This means that the disk can
       keep  an  albeit  corrupted  (maybe  slightly)  but  inaccessible   and
       unerasable  copy  of  some of your data.  Modern disks are said to have
       about 100% transparent remapping capacity.  You  can  have  a  look  at
       recent discussions on Slashdot.

       I  hereby  speculate that harddisks can use the spare remapping area to
       secretly make copies of your data.  Rising totalitarianism  makes  this
       almost a certitude.  It is quite straightforward to implement some sim‐
       ple filtering schemes that would  copy  potentially  interesting  data.
       Better,  a  harddisk  can  probably  detect  that a given file is being
       wiped, and silently make a copy of it, while  wiping  the  original  as
       instructed.