The marginal groups comprises of the people who occupy the lowest ranks on social ladder, socially and economically and the resources are inaccessible to them.
As London grew, crime flourished. We are told that 20,000 criminals were living in London in the 1870s. We know a great deal about criminal activities in this period, for crime became an object of widespread concern. The police were worried about law and order, philanthropists were anxious about public morality, and industrialists wanted a hard-working and orderly labour force. So the population of criminals was counted, their activities were watched, and their ways of life were investigated.