Marjorie McMillan, head of radiology at a veterinary hospital, found out by reading a letter to the editor in her local newspaper. Pamela Goodwin, a labor-relations expert at General Motors, happened to see a computer printout. Stephanie Odle, an assistant manager at a Sam's Club store, was slipped a co-worker's tax form.
Purely by accident, these women learned they were making less than their male or, in Goodwin's case, white colleagues at work. Each sued for pay discrimination under federal law, lucky enough to discover what typically stays a secret. "People don't just stand around the watercooler to talk about how...