Winny.

It is a Peer-to-peer(P2P) software.
It enables to share specific files directly with innumerable anonymous people, without the presence of any server.

Not only winny, but also any other P2P software are very convenient for people who wish to make illegal sharing of files with copyright, especially in musics or movies.
Since these softwares secure anonymity, police have difficulty in specifying who made illegal sharings.
Actually, there are arrested people with a suspicion of illegal sharing of files, but they were specified with external factor, such as announcement of illegal sharing in bulletin board or blog.

Kaneko, the one who made winny, was arrested too, on suspicion of "aiding and abetting an infringement of copyright".

Winny users are rapidly increasing, which is said to be about 600,000 to 1 million. (it is difficult to determine, because of it's anonymity.)
But are they really secured?
Unfortunately, I have to answer "NO!".

A group of virus called "Antinny" were made and scattered through winny.
These virus allows "any" files on PC to be shared, or in other words, it makes disclosure.
Since when the PC is infected, the user can't choose the files to share, thus the information leak.

And this is becoming a serious problems in Japan.

- from City Hall, about personal information of citizens
- from Post Office, about delivery of mails
- from Hospital, about diagnoses of patients
- from TV Station, about personal information of casts in a TV Program
- from Police, about criminal investigations and the criminals
- from Prison, about prisoners
- from the Ministry of Economy, Trade and Industry, about inspection of Nuclear Power Plant
- from Airline Company, about PIN number for entering restricted areas
- from Self Defense Force, about personal information of soldiers and 'classified' materials

And many more were leaked.
Those workers brought home the secret information, and copied to private PCs which use winny to continue their work.

As a property of winny, once the file is shared, it goes around the world semipermanently and never can be deleted, unless to delete all the data of winny users.

Even Koizumi warned nation not to use winny, especially in public service.
It is unusual that the government warns nation to restrain in using a particular software.
But do they really understand what is the problem?
Winny is not a virus.
These leakages may have been prevented, if the system of information management was thoroughgoing.
The real problem may be "bringing home the secret information".

Antinny practically have a property of punishment against an infringement of copyright.
Hence, there are some internet users who sneers to the infected ones rather than sympathize them.
But on the other side, Mass Media reports about these leakage of information day after day, but consistently reports the infected ones as "victims", and never touch the other side that they may be invaders who made illegal downloading.
Even the police, who have determined the existence of winny as illegal and arrested Kaneko, were using winny too.
But they will never be focused, neither by Mass Media nor the government.
Moreover, Antinny were widespread since 2004 and it's danger was recognized on earlier time, and there is a case that the victim accused the user of responsibility and developed to the demand of compensation for damages trial, but these are ignored.

By the way, Kaneko said in his seminar that he can rewrite the program of winny to prevent scattering of virus, but he is restricted by police to update.
Well, I think police should recognize the importance of updating software.
Updating is a battle against bugs and virus, and stopping it means allowing it to be an easy target.
In fact, some people say that arresting Kaneko was wrong decision.

We should be aware of vulnerability of computer.
Who had ever thought that a software made by a single person may lead a nation to a crisis in military way?