Google said its fleet of cars responsible for photographing streets around the world had for several years accidentally collected personal information - which a security expert said could include email messages and passwords - sent by consumers over wireless networks.
The company said last night it is currently reaching out to regulators in the relevant countries, which include the United States, Germany, France, Brazil and Hong Kong in China, about how to dispose of the data, which Google said it never used.
"It's now clear that we have been mistakenly collecting samples of payload data from open (i.e. non-password-protected) WiFi networks," Google senior vice president of engineering and research Alan Eustace said in a post on Google's official blog.
For Google, whose Internet search engine handles more than two-thirds of all web searches in the US, the issue could mark an embarrassing blow to its reputation as a trusted custodian of consumers' personal information.
And the revelation comes at a time of increasing concern among consumers and regulators about the way that websites handle users' personal information.
Last month, four United States senators sent a letter to Facebook expressing concern about recent changes to the service and the company's privacy practices.
Marcia Hofmann, a senior staff attorney at the Electronic Frontier Foundation, said the fact that Google collected the data by accident would probably protect the company from liability under the federal wiretap law, which prohibits unauthorized access of communications.
"To violate the law requires that the interception was intentional," said Ms Hofmann.
But she noted that she did not know how Google might fare under laws in other countries and said she thought it was possible that some countries might step up regulatory scrutiny of Google's privacy practices in the wake of the incident.
A Google spokesperson said the Street View cars have been collecting the information since 2006 in more than 30 countries, including Ireland.
Reuters