That's rather an alarmist post based on lack of information.
DBAN
About DBAN | Darik's Boot And Nuke is a well known utility developed by the open source community over many years.
It surpasses all of the US data destruction standards including those for the DOJ and the Department of Defense 5220-22.M standard.
Do not confuse this with software found on the covers of PC magazines which often run within a Windows shell leaving bits of files all over the place.
DBAN boots into it's own shell giving complete access to the drive locking out other write processes.
The commercial version uses the same algorithm but is for corporations who need tech support and third party indemnity insurance.
It's widely used in the UK by IT departments for recycling computers including those in schools and banks. It simply isn't practical to remove the hard disk out of an expensive laptop and destroy it when someone leaves or moves on.
This a quote from a commercial data deconstruction company;
"We utilize DBAN to facilitate our disk wipes. It's a simple yet effective tool. You may notice that this tool is based on free software, notably under the GNU General Public License.
Free software allows us to charge less, as we aren't trying to pay for expensive licenses. But don't worry, the software we utilize is well supported and in use around the world by large corporations, educational institutions, and government offices alike."
Unless you are the FBI with access to $5m electron microscope forget it, it's gone -
Some ref links;
Data Destruction
Data Destruction : a DBAN Test
Moundalexis.com: Disk Wipes & Data Destruction