A sock puppet describes an additional account created by an existing member of an Internet community, sometimes to manufacture the illusion of support in a vote or argument. Other reasons include a desire to support or vote on an issue coupled with a desire to have one's "main" account stay away from the issue. This behaviour is sometimes seen as being dishonest by online communities, and as a result these individuals are often labeled as trolls.
One type of sock puppet is sometimes referred to as a "straw man sock puppet". They are created by users with one point of view, but act as though they have an opposing point of view, in order to make that point of view look bad. They will often make poor arguments which their "opponents" can then easily refute. This can allow them to make straw man arguments. Such sock puppets thus become a personification of the straw man argument which their creators argue against. They often act as unintelligent or uninformed, and may behave in an overtly bigoted manner. The effect is often to obfuscate the debate and prevent a serious discussion of the arguments from each side. Suspicion of such sock puppets is often harder to verify though, as there are often people who naturally behave in such a manner with the same effects.