Where inclination, power and isolation join, violence is ever more likely. Attacks on farmers and on farm labourers have in common an inequality in power, however brief, and seclusion. Soviet leader Josef Stalin, who hated peasants as much as Nicolai Lenin, killed as many as 40 million Russians, mostly small farmers. The Chinese communist ruler Mao Zedong massacred between 30 and 60 million of his own people. Both got away with it.
Race is sometimes no more than an added pretext for cruelty.
Prisons, armies and police services allow some people to exercise abnormal authority over others. Police services have the misfortune to attract both those dedicated to serving justice and order, and a percentage of bullies, for whom unbridled authority has a special appeal. At a time when violent crime is at its worst and the stresses of policing are extreme, any flaws manifest themselves all too readily in suicide and undue violence. The video footage shown on SABC, of six police officers training dogs on screaming prisoners, showed extreme brutality. Illegal immigrants are surely among the most defenceless of people, unlikely to report assaults on themselves.