In the case of traditional phones such as feature phones, terminal manufacturers have incorporated a protection mechanism called "secret mode" or "privacy mode" in their phones by developing dedicated application software and dedicated content file formats as a set.
On screen, he even had a cameo in the feature film The Terminal: When a hapless traveler played by Tom Hanks is finally released from airport purgatory, he heads straight to a club to meet Golson one of his idols.