Clearly, most of you weren't around for the Vietnam War. There were two major umbrella organizations that controlled the size, locations, dates and "thrusts" (themes) of the protests, antimilitary actions, recruitment of members: The People's Coalition for Peace and Justice and the New Mobe, The PCPJ was an instrument of the Communist Party USA and the New Mobe was an instrument of the Socialist Worker's Party.
Both of those organizations got instruction, direction, and some funding from Moscow, Beijing, and Hanoi throughout the war.
These professional agitators come from the same anti-US organizations as always and follow the same patterns. And then, as now, our dear government knows all about them but doesn't do anything at all to stop them.
Indeed. The international communist “left” have been at this since the 1950s.