How did marginal groups threatened the city of London? What was the root cause of this problem?

How did marginal groups threatened the city of London? What was the root cause of this problem? How did they authorise in London to try to solve this problem?

AS London grew, crime forced and became a matter of concern for the police and philanthropists 20,000 criminals were listed living in the city who were infact poor people and lived by stealing lead from roofs, food from shops, lumps of coal and clothes drying on the hedges. The cheat, tricksters, pick pockets and petty thieves disturbed the law and order situation of the city. This happened due to mismatch between huge influx of labour from surrounding rural areas and the opportunities available to earn livelihood.
In an attempt to discipline the population, the authorities imposed high penalties for crime and offered the work to those who were considered the deserving poor.