Yes, phone phreaking was where Steve Jobs got his start in life. Then he graduated to stealing intellectual property from Xerox, and the rest is history.

While I am no fan of Mr Jobs. Apple did go to the trouble of licensing the technology in question from Xerox. The real crime was that Xerox gave it away for a pitance. Anyway, the more talented of the Steves, (i.e, Woz) built the blue boxes. Jobs sold them in the dorms at Cal.