Suburbanite carbrains: "High density is dangerous! More people means more crime! You could be murdered right outside your tiny apartment!"
Correlation-causation fallacy. More people close together does not cause crime. Poverty causes crime. High density areas reveal a more accurate cross section of society, including the lower class which are much less stable, have fewer good opportunities, and thus more likely to turn to crime.
High density living is not what's dangerous here. Capitalism is.