
The first time I called into an elevator, I picked up my iPhone and dialed the number—labeled on my list as the Crown Plaza Hotel in Chicago—and immediately heard two beeps, then a recording of a woman's voice, who told me to press one to talk.
After just one ring I heard a series of four tones and was immediately listening to the inside of another elevator.
This time I heard a few muffled voices, then a woman answered: "There are people in here, yes."
"Turn it over," I heard a woman's voice say in a Midwestern accent.
This was my introduction to the illicit thrill of elevator phone phreaking.
I had learned about this hobby—and received my list of working elevator phones—just a few days earlier from Will Caruana, a thirtysomething freelance security researcher.