THE PHONE RANG AND A STRANGER CRACKED SING-SONGY AT THE OTHER END OF the line: “Happy Birthday.” That was spooky–the next day I would turn 37. “Your full name is Adam Landis Penenberg,” the caller continued. “Landis?” My mother’s maiden name. “I’m touched,” he said. Then Daniel Cohn, Web detective, reeled off the rest of my “base identifiers”–my birth date, address in New York, Social Security number. Just two days earlier I had issued Cohn a challenge: Starting with my byline, dig up as much information about me as you can. “That didn’t take long,” I said.