Categorial social groups have been studied with more interest by the European social psychologists after Second World War. This research has been supported on the increase of this kind of group in the reality of social relations and in its effects on production of social identities. In this work we indicated how the importance of the categorial social groups goes along with the imaginary group fainting. Groups have become outline presences than organizations based on relations. We nominated name-group these virtual groups, which doesn't have organic but only imagetic existence. Nowadays, name-groups are more common than "live" groups and this contributes to unreliable individual relationships and also makes possible people move to another group like changing clothes. Effects of name-group incidence are the least presence of "live" face to face groups, the ampliation of social control mechanisms and the growth in social violence.
social identity; groups; imaginary; virtual