A computer potato is one who downloads media through file sharing networks such as bit-torrent and spends much of their time watching shows obtained. The type of media could range from movies to anime to japanese drama episodes.
Dude, that guy stays in his room and watches shows on his computer all day long. He's such a computer potato!
When a person uses the computer rather then getting exercise.
Person 1 " Dude, I just got so much gold off my sword!"
Person 2 " GETTA LIFE, YOU FUCKING COMPUTER POTATO ! "