Concentration of people with the same aim. Communal Act. In an act of collective or mass are supporters of a political party, the supporters of a team, a group of demonstrators or bars. It means that everything you do or say is everyone's responsibility.
He said they act carried out by a set of individuals who have the same purpose or acting under the same parameters, values or intentions. For example, a collective Act can be a strike, demonstration, concentration in defence of or against something.