Final answer:
The claim that Special Access Programs have always been public knowledge is false; these are highly classified information safeguards with restricted access, often surrounding sensitive government undertakings.
Step-by-step explanation:
The statement that the existence of Special Access Programs (SAPs) has always been public knowledge is false. SAPs are security protocols that provide highly classified information with safeguards and access restrictions above and beyond those for regular classified information.
The existence of some SAPs is not public knowledge by design, as they often cover highly sensitive government projects, operations, or technology. Over time, certain SAPs might become declassified or acknowledged, but this is not always the case.