Early Hackers Used Whistles from Cap’n Crunch Cereal Boxes
&quot;Secrets of the Little Blue Box,&quot; Ron Rosenbaum&#x27;s classic October 1971 Esquire article: <a href="https:&#x2F;&#x2F;classic.esquire.com&#x2F;article&#x2F;1971&#x2F;10&#x2F;1&#x2F;secrets-of-the-blue-box" rel="nofollow">https:&#x2F;&#x2F;classic.esquire.com&#x2F;article&#x2F;1971&#x2F;10&#x2F;1&#x2F;secrets-of-the...</a>