Fansub

Fansub - short for "fan subtitled"; a version of a movie or television show which is in the original language, but has been subtitled by "fans" or a subtitling group. These are usually not authorised by the copyright holders and therefore illegal, but those done of shows unlicenced in the language of the subtitles are nearly never prosecuted. Usually this term refers to anime. These are most commonly found through peer to peer software or IRC.