I have heard this phrase repeated so many times in the advertisements for protectors/packers that it's become almost cliche. Such techniques have been around for over 20 years. Using the debug registers to store the decryption key is relatively well-known - and defeatable (this is 5+ years ago):
http://reversinglabs.com/newsroom/blog/lockpicking-telock.ht...
On the other hand, I like how the article presents the negative aspect too - that security features can be used to make systems secure against their owners is a point that I definitely believe needs to be more prominent among the public.