Exhaustive testing: Is when either the tester or the funds are exhausted, it has no bearing on the number of bugs yet to be found.
Nothing new. The problem of bugs in systems has always been with us in design, it is just that computers probably give more opportunities for error.
Ask the captain of the BA flight that lost two donkeys on short finals into LHR. That bug in the fuel system had managed to hide itself for several years, before raising its ugly head.
