This article rightly celebrates the Carterfone story. This is the successful mix of technological innovation and policy transition, which established the idea of adding applications to someone else's network.
Nice final paragraph:
It was June 26, 1968 when the FCC acted on Carterfone. Robert F. Kennedy had been buried two weeks earlier. In Czechoslovakia, followers of the "Prague Spring" fought against Communist rule. Students revolted against mindless bureaucracies at Columbia University, in Paris, in Seoul, in Mexico City. In these stormy times almost no one noticed as the FCC's Commissioners quietly rebelled against the world's biggest telco, unleashing the future.