Photo/Illutration This operator of an information technology company purchased through an Internet auction site hard disks that contained public information compiled by the Kanagawa prefectural government and not wiped from the disk. (Tatsuya Sudo)

A man who won an Internet auction for used hard disks soon discovered that he was in the possession of confidential and sensitive government information that he had no business reading.

At first, the man, who owns an information technology company, was puzzled when he found repeated mention in the file names of Kanagawa Prefecture.

But he was in for a greater shock when he used recovery software and found that the files on the hard disks contained mountains of data compiled by the Kanagawa prefectural government.

The data included everything from individuals who were behind on their taxes and the amount; documents considering the seizure of assets; documents related to contract bid amounts; rosters of employees at public schools; and even design blueprints for electric power plants and water supply works.

The man regularly purchased used hard disks through Internet auctions because it was cheaper than buying new ones. Three new hard disks usually cost about 100,000 yen ($920) or more, but through Internet auctions he bought three used hard disks for about 10,000 yen.

When he inserted one of the hard disks, the computer flashed an error message. Having faced a similar problem in the past, the man felt that the data on the hard disk had not been wiped properly.

To avoid further error messages, the man began reading the data on the hard disk and found a list of file names, with many having Kanagawa Prefecture in the name.

Thinking that he would be unable to ascertain the contents of the hard disk just through the file names, the man purchased recovery software available for under 10,000 yen and restored the data found in hundreds of files. The files contained not only documents and spreadsheets, but also photos and videos.

Reading through some of the files, the man became convinced that the information could only have been compiled by the Kanagawa prefectural government.

The man found that the seller had placed other hard disks made by the same company up for sale on the Internet auction site. The man in the end purchased a total of nine hard disks, containing a total memory storage capacity of 27 terabytes.

He stopped counting the number of files he restored at about 50 million because his computer stopped working.

Feeling he could not simply ignore what he found, the man contacted The Asahi Shimbun. Reporters made inquiries with the Kanagawa prefectural government and determined that the serial numbers on the hard disks purchased by the man matched those the Kanagawa prefectural government had replaced on its computers acquired through Fujitsu Leasing Co.

The hard disks had been made available on the Internet auction site by a male employee of Broadlink Co., which was commissioned by Fujitsu Leasing to wipe the data from replaced hard disks. The employee was in charge of wiping the data, but he instead pilfered a number of the disks and posted them on the auction site.

While the operator of the information technology company placed the brunt of the blame on the Broadlink employee, he was also critical of the lax computer security measures taken by the Kanagawa prefectural government.

"Why did it allow for reformatting of hard disks that made it possible for the data to be restored using easily available software?" the man asked. "Why wasn't the data encrypted when stored and why weren't government officials on hand to witness the destruction of the hard disk?"