This paper calls our attention to the need of investigating how our increasing reliance on communication technologies to mediate social interactions influences the formation of publics. Here a public is defined as an association of strangers united by an awareness of their commonalities. This union creates a potential for collective actions and a capacity to actively influence the state of our society. Framed by this definition and a discussion of the processes by which publics are formed, the paper then outlines some of the main questions to consider when studying the influence of communication technologies to mediate the formation of publics. These questions relate to our capacity to 1) develop shared conditions, interests and purposes, 2) uncover these commonalities, and 3) develop an awareness of forming a public capable of action.