About 1.8 million people in Japan are active users of file-sharing software, a sharp increase from a year ago, according to a survey by the Recording Industry Association of Japan (RIAJ), TV broadcasters and other industry groups.

The figure is equal to about 3.5 per cent of all internet users and represents a jump from last year's survey, which put the number at about 1.3 million, or about 2.7 per cent of internet users. The survey was conducted online in mid-June and gathered 18,596 responses.

The average number of downloads per user per year was 194 files, of which about 87 were music, 79 were movies, 11 were images, nine were software applications and eight were documents.

The most popular file-sharing application is Winny, according to the survey; WinMX was second and Limewire was third. BitTorrent clients, popular in the West, were fifth on the list, with only 6 per cent of people using them.

Winny has become known for being at the root of a string of information leaks. Viruses that open a user's entire hard disk to the Winny community are prevalent on the file-sharing network, and it is through those that reams of confidential information, from customer data to military plans, have been leaked online.

Perhaps related to this, viruses were the top reason people who previously used file-sharing software cited for giving up the habit. Fear of getting caught or prosecuted for illegal file-sharing was low on the list.

In contrast to the mass-lawsuit approach that the Recording Industry Association of America (RIAA) has used, the RIAJ has been going after only a handful of people each year. In each case it tries to force a settlement with the user prior to legal action, and as a result there have been almost no prosecutions for file sharing.