Nazi terror was not arbitrary, but was focussed on the persecution of the 'enemies of the people', or 'community aliens'. These outsiders - habitual criminal offenders, gypsies, homosexuals and others were defined by Nazi ideology. Down to the late 1930s - until the mass arrests of the Jews in the wake of 'Kristallnacht' - major concentration camps such as Buchenwald or Sachsenhausen incarcerated more of these social outsiders than they did communists or Jews