The California Public Employees' Retirement System, the largest U.S. public pension, said it accidentally printed the Social Security numbers of nearly a half-million retirees on brochures mailed out last week.
A mail-processing computer inadvertently added the partial or full Social Security number of each retiree on their mailing label attached to a brochure sent to 445,000 people announcing an upcoming board election, said Calpers spokesman Brad Pacheco. The fund sent letters to its members apologizing and promising new procedures to prevent future mix-ups.
Social Security numbers are often used by identity thieves to access credit accounts and steal money and products. An April 2007 report by the federal Identity Theft Task Force identified the Social Security number as "the most valuable commodity for an identity thief."
The Social Security number on the mailing "appears as a sequence of numbers without hyphens," Pacheco said.
"There is nothing on the address panel that identified the series of numbers as a Social Security number," he said. "While it is unlikely that someone would recognize the series of numbers as being a Social Security number except our members, we consider this an unfortunate and serious incident."