The “Blue Box” was also used to call BBSs around the world. (via a 2400 bps Hayes or US Robotics at that time.)
After Telenor’s network was fully digitized in 1997 (the replacement started in 1986) this type of “Blue Boxing” was history.
Many years earlier, Blue Boxes became known first through an article in the magazine Esquire written by John T Draper (AKA Captain Crunch). Somewhat more familiar may be the story of Steve WOZniak and Steve Jobs before they started Apple together.