File sharing is a great way to distribute film, music and software online. Unfortunately, it’s also a great way to get into trouble for sharing illegally gathered files or to download viruses hidden in such programmes. The question is, do the costs outweigh the benefits? A HD movie takes up multiple gigabytes. If multiple computer users try to download it simultaneously, the server is bound to collapse.

But decentralized peer-to-peer file-sharing networks get around this problem by allowing quick data transfers online, made possible because the network is made up of multiple users who have installed special client software.

Most fee-based services store user’s files on a server from which others can access it in a semi-encrypted form that makes the user’s IP address unreadable.

“The network distributes the contents in pieces via multiple end-use devices,” explains Volker Zota of the German computer magazine c’t. It’s also much quicker than a direct connection to a site when multiple users are online.

But the dangers remain. Much of the content shared on networks like Bittorrent and Gnutella have been posted online illegally.

“Using these distribution networks, in and of itself, is not illegal,” says Munich lawyer Jan Christian Seevogel. But, in most cases, the downloads are illegal since the network users have no rights to offer or download the contents.

Seevogel says the safest thing to do is keep a safe distance from movies and music that are usually sold for money or are currently in theatres or on the charts.

However, there are legal alternatives for using the networks. For example, there is no legal problem with relaying self-composed and performed songs or self-made videos. And ever more contents and open source software is coming out with a special license, akin to the Creative Commons (CC), says Seevogel.

The CC label means that the use, copying, distribution and, in some cases, altering of the contents is allowed. A search for CC content can be conducted at http://search.creativecommons.org.

But downloading files without checking their legal status first can be dangerous and have harsh consequences if film and music industry investigators discover a person’s IP address when researching illegal uploads and downloads.

Most punishments are civil in nature, says Seevogel. Artists and production companies tend to try to protect their intellectual property with warnings, cease and desist orders and, in the worst case, a damages claim.

A further risk in file sharing is accidentally downloading a virus or other malevolent software, says Thorsten Dietrich of Germany’s Federal Office for Information Security. Additionally, using the client opens up a sustained connection in a PC or router’s firewall.

“Your own PC is, thus, directly reachable from outside, which raises the risk of a targeted IT attack,” Dietrich says.

In general, file sharing via peer-to-peer networks is on the retreat since a lot of content owners are applying pressure, says Zota. Hosts like Rapidshare, Netload and Uploaded.com have all fallen victim to the trend.

Meanwhile, usenet networks are experiencing a renaissance.

Originally designed as discussion fora, they now allow data to be transferred. Firstload, Usenext and iLoad all operate on the store and forward principle, says Seevogel. That means multiple servers are constantly trading data back and forth, while protecting the IP addresses of the traders from third parties.

“The industry still hasn’t come up with enough alternatives to the trading platforms,” says Axel Schmiegelow of the German Federal Association of the Digital Industry. But some are trying.

Fans of television series can sometimes find their favourites on Youtube. And many broadcasters have started video-streaming services along with their fee-based services. “Watch instead of download” is their motto.

As for music, there are legal streaming sites now like www.spotify.com or www.soundcloud.com.