Confusion over the legality of BitTorrent arises from the fact that it can be used to download and share copyrighted materials, such movies, games and music. While this is an illegal practise, there is nothing illegal about BitTorrent itself. The software is simply a tool for transferring files- it can be used for both legal and illegal file sharing. Downloading pirated material is illegal, but owning the BitTorrent software is still legal.
When a user downloads a file with BitTorrent, it passes from one user to the next (peer to peer technology). In order for the next person to get the file, the user must ‘seed’- letting other users download the completed file from them. After downloading a file, it is a courteous practise for a Bit Torrent user to leave it seeding for a while, to continue the chain of sharing.
‘Leeching’ in BitTorrent terminology is the opposite of seeding. Seeders ensure that others are able to download a file after they have, but leechers download a file and then cut the connection. This breaks the chain of downloading from one peer to the next. The leecher benefits from the seeding work of others without passing on the favour, so it’s considered poor practise.
A peer is simply a user of bit torrents. Peer to peer technology refers to sharing files from one user to the next, as opposed to each user downloading a file from one central server. After the initial uploader of a file has seeded for a while, it passes from peer to peer, without needing the originator to be online.
Seeds are users who have downloaded the entire file and are now uploading to other users, providing a complete copy of the file for the next user. The more seeders are available, the more likely a user can find a high-speed connection. Peers can slow the process if they greatly outnumber seeders, as each one must share the connection, but over time will speed things up if they seed afterwards.
Share ratios are usually measured by private torrent sites. This refers to the ratio of download to upload- leeching to seeding. A 1:1 or 1.0 ratio means that a user has downloaded and uploaded the same amount. A 0.8 ratio indicates that you have uploaded less than downloaded. Some private sites have a minimum ratio allowed by users, to ensure that everyone contributes to the community.
Trackers are a special type of bit torrent server that assists in the communication between peers. The tracker makes torrent sharing possible by directing each new peer’s connection to the peer they need to download from. Trackers are no longer essential but they can improve the speed of connections. They can also be used to trace torrent activity.
The use of BitTorrent is inherently safe, but risks are introduced depending on where users find their files. Sharing known files between friends is safe because the source is trusted, but downloading from public websites does carry the chance that the torrent contains suspicious files, such as malware and viruses. Some sites go to lengths to verify the integrity of uploaders, for this very reason.