“The spark that ignited their partnership was provided by Mr. Wozniak’s mother. Mr. Wozniak had graduated from high school and enrolled at the University of California, Berkeley, when she sent him an article from the October 1971 issue of Esquire magazine. The article, “Secrets of the Little Blue Box,” by Ron Rosenbaum, detailed an underground hobbyist culture of young men known as phone phreaks who were illicitly exploring the nation’s phone system.” – John Markoff, The New York Times (Last accessed October 6, 2011)
The History of Phone Phreaking Blog has a scanned copy of the October 1971 Esquire magazine article “Secrets of the Little Blue Box.” (PDF 9.8 MB)
There’s an HTML / text version of “Secrets of the Little Blue Box” at lospadres.info.