The practice of using multiple accounts and/or logins to manufacture the appearance of Internet Fame. The term recently jumped into meme lexicon because of a series of posts by a younger gamer named "plops" that was so transparently bad at cheerleading himself with his own forum logins, that he was laughed off the forums by most of its readers.
Douchebag 1: Hey, I'm douchebag 1! I'm famous for (fill in pointless internet thing nobody cares about).
Douchebag 1's anonymous login: Yeah he is famous for that! He's da greatess evar!!!
Everyone: Man, stop the plopping samefag.