The massive computer breach against Anthem, the nation's second-largest health insurer, exposes a growing cyberthreat facing health-care companies that experts say are often unprepared for large attacks. Hackers gained access to the private data of 80 million former and current members and employees of Anthem in one of the largest medical-related cyber-intrusions in history. Authorities said the breach, which was discovered late last month and disclosed this week, did not involve private health records or credit card numbers but did expose Social Security numbers, income data, birthdays, and street and e-mail addresses.
