Hardness of security and safety

Eugene H. Spafford is quoted to have said:

The only truly secure system is one that is powered off, cast in a block of concrete and sealed in a lead-lined room with armed guards - and even then I have my doubts.

I guess the quote could just as well have been about safety:

The only truly safe system is one that is powered off, cast in a block of concrete and sealed in a lead-lined room with armed guards - and even then I have my doubts.