Multimedia

Source: Associated Press

The popular video-sharing site YouTube has moved to purge terrorists training films and other videos that extremist groups might use to attract new members, an imperfect process that will rely on users to report objectionable videos.

It's sort of like the post Sept. 11 advice — if you see something, say something. It's nearly impossible to vet every video when 13 hours of new video are uploaded every few minutes.

A quick search on Google-owned YouTube on Friday, one day after the new policies were posted, turned up several videos on how to make bombs using, for instance, such household items as toilet bowl cleaner and tin foil.

In addition to barring terror training videos, the new YouTube community guidelines include bans on videos that incite others to commit violent acts, videos on activities such as how to make bombs and footage of sniper attacks. Previously, it had policies in place against showing people "getting hurt, attacked or humiliated," banning even clips OK for TV news shows.

YouTube has not identified specific videos on its site that led to the change, nor said exactly how it will choose those that are purged. YouTube does not deny that extremist groups could have used the site.

What is Bittorrent?

BitTorrent is a protocol designed for transferring files. It is peer-to-peer in nature, as users connect to each other directly to send and receive portions of the file. However, there is a central server (called a tracker) which coordinates the action of all such peers. The tracker only manages connections, it does not have any knowledge of the contents of the files being distributed, and therefore a large number of users can be supported with relatively limited tracker bandwidth. The key philosophy of BitTorrent is that users should upload (transmit outbound) at the same time they are downloading (receiving inbound.) In this manner, network bandwidth is utilized as efficiently as possible. BitTorrent is designed to work better as the number of people interested in a certain file increases, in contrast to other file transfer protocols.

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