In Night by Elie Wiesel, how did the Kapos treat their prisoners?

During the Holocaust, as depicted in Night by Elie Wiesel, some kapos were Jewish prisoners themselves. Kapos treated the other Jewish prisoners cruelly because if they did not, they would be punished or killed by the Nazis. Any kapo who was easy on the prisoners was quickly removed from his/her duties. The Nazis picked the biggest, strongest, prisoners for the job. Gypsies were also often chosen to be the kapos for the prisoners, and they were said to be even worse than the others but because the camps were filled with more Jews than anyone else, there were kapos who were Jewish. Probably the most memorable kapo in Night was Idek, the man in charge at the electrical warehouse where Elie and his father were sent to work. He was known for his fits of brutality, and Elie's father and Elie suffered greatly at his hands.