The Census Bureau, the main collector of information about Americans, lost 672 computers. Of those, 246 contained some personal data, the department said in a statement. However, no personal information from any of the missing computers has been known to have been improperly used, the department said.
The number of people affected by the equipment losses could not be determined, the department said.
"All of the equipment that was lost or stolen contained protections to prevent a breach of personal information," said Commerce Secretary Carlos M. Gutierrez. "The amount of missing computers is high, but fortunately, the vulnerability for data misuse is low."
More than 30,000 laptops were used within the department's 15 operating unit since 2001, the department said, and a total of 1,137 were stolen or missing.
Fifteen handheld devices used to record survey data for testing processes in preparation for the 2010 Census also were lost, the department said. The department was in the process of contacting the 558 households with data recorded on the missing devices, although because of encryption technology, the risk of data misuse was considered low, it said.
A half-dozen other federal agencies or departments have reported data thefts and security breaches involving personal information in the last six months.
The Veterans Affairs Department suffered the biggest loss with the theft in May of a laptop and external drive containing information for 26.5 million veterans and active-duty troops. Burglars stole the equipment from the home of a Veterans Affairs employee, but the computer was later recovered and showed no signs of having been accessed for the personal data.
Other government departments reporting the loss of computers with personal information include the departments of Agriculture, Defense, Education, Energy, Health and Human Services and Transportation. The Federal Trade Commission also has lost laptops with sensitive data.