It began in 1997 as a company that sold credit data to the insurance industry. But over the next seven years, as it acquired dozens of other companies, Alpharetta, Ga.-based ChoicePoint Inc. became an all-purpose commercial source of personal information about Americans, with billions of details about their homes, cars, relatives, criminal records and other aspects of their lives. As its dossier grew, so did the number of ChoicePoint's government and corporate clients, jumping from 1,000 to more than 50,000 today. Company stock once worth about $500 million ballooned to $4.1 billion.