They were cheap and available

On 20 August 1947 Gerhard Rose, one of Germany's most respected physicians, stood in the prisoner's dock at the Palace of Justice in Nuremberg, Germany, awaiting his sentence for "murders, tortures, and other atrocities committed in the name of medical science." Dr Rose, the department head for tropical medicine of the Robert Koch Institute, was on trial along with 22 of his medical colleagues, for perpetrating "ghastly" and "hideous" experiments on concentration camp prisoners during the war. At one point in the trial when the chief prosecution witness, Dr Andrew C Ivy of the medical school of the University of Illinois, underscored the basic principle "that human experimental subjects must be volunteers," Dr Rose and his defence counsel vigorously objected, arguing that the United States was guilty of similar medical practices and giving several examples to support this contention. (BMJ: They were cheap and available)