Thomas Sowell -

 Activism is a way for useless people to feel important, even if the consequences of their activism are counterproductive for those they claim to be helping and damaging to the fabric of society as a whole.

Edward Bernays -

No serious sociologist any longer believes that the voice of the people expresses any divine or specially wise and lofty idea. The voice of the people expresses the mind of the people, and that mind is made up for it by the group leaders in whom it believes and by those persons who understand the manipulation of public opinion. It is composed of inherited prejudices and symbols and clichés and verbal formulas supplied to them by the leaders.