However, critics such as Bloys and Ostergren dismissed arguments that public records have long been available in paper form as specious.

"The simple truth is these records were safe in the courthouse for 160 years," Bloys said. Now all it takes is Internet access and a rudimentary idea of how to look for sensitive data to find all sorts of information, he added.

Ostergren claimed that simply by "messing around" on county Web sites over the past three and a half years, she has found hundreds of thousands of pages containing sensitive information. She has printed out more than 17,000 records containing people's Social Security numbers, the maiden names of their mothers (often used to verify identities) and the names of minors.

Among the countless nuggets that Bloys said he has found online was the complete medical history of a terminally ill government official in the Texas county of Fort Bend.

Buying Data in Bulk