Overwrite

Hi,

I've looked around for the answer to this but can't seem to find it, apologies if I've missed it.

Does the overwrite files option shred any files in the trash folder (in Ubuntu or the recycle bin in windows)? Also, does anyone know if the overwrite option overwrites file slack?

Thanks for your help,

Further to the earlier discussion about BleachBit's one pass overwrite
functions and whether BleachBit should use more than one pass for it's over wrting pattern:
http://bleachbit.sourceforge.net/forum/bbs-simple-overwrite-not-explaine...

"Studies have shown that most of today’s
media can be effectively cleared by
one overwrite." ?

Can anyone explain what happens why I enable he overwrite function with BB, how does it ensure the data cannot be recovered if I overwrite a file on a hard disk or usb stick?

I do think BB is a great solution for Linux, but how can I trust a functin that just says overwrite with no explanation of what is meant by this term, from a technical stance.

Under BB's preferences options why not enable users to choose standard secure erasing patterns like:

Gutmann method
http://en.wikipedia.org/wiki/Gutmann_method

AFSSI-5020
http://en.wikipedia.org/wiki/AFSSI-5020

DoD 5220.22-M