Based on the results of previous research of the research group at the Institute for Research in Humanities and Social Sciences (UNLP-CONICET) on social networks in different types of libraries (research, academic, and popular) in Argentina, it makes a balance on its use in these institutions and guidelines for the development of a communications policy that contemplates and part of the management plan of these information units are proposed. They point to consider all aspects related to the scope, limitations , uses, risks and others involving the adoption and appropriation of different social networks (such as Facebook , Twitter , etc.) , their coexistence , management and sustainability to over time