Hi Chris & Allan,

Thanks for hosting such a great show. I listen to every episode of TechSNAP (audio version while commuting) and love the news and quality learning information you guys give back to the community. Keep up the good work!

My question is...
Are magnetic wiping tools such as Shred http://linux.die.net/man/1/shred and Wipe http://wipe.sourceforge.net/ still useful with changes in technology to today's 2 and 3TB harddrives.
I know they were used on magnetic harddrive 15 years ago, but I am reading that today's magnetic harddisks are so small and compacted that a single wipe will prove unrecoverable and these tools are now obsolete.

Is wiping a magnetic harddrive 3 or more times really nessesary before selling it on eBay if it had confidential information on it?

Please note I am talking about running
#shred /dev/sda
to wipe an entire disk (the whole block device), not a single file on a filesystem or partition.

Also do the tools work on flash memory (SD card for example, not SSD)?

Thanks for taking the time to answer my question - hope it makes it onto the show :)

Kind Regards

Simon