No less valid than this I would suggest.

It doesn't cover securing the system, it doesn't really cover how to break the system
At any rate, Thumbs Down, this isn't a tutorial, doesn't belong here, and none of the information is explored sufficiently. Why is it a cursory mention of "this can be done" is acceptable around here anymore?
"Why is it a cursory mention of "this can be done" is acceptable around here anymore".... Hmmm.... That "tutorial" was from nearly three years ago..... Oh well..... Things don't change I guess......