Defensible space improvements in high-crime areas face two nearly insuperable obstacles: the fact that offenders are probably largely insiders with intimate local knowledge and the presence of preexisting social characteristics that hamper informal social control. However, the principles proposed by Oscar Newman in his book, 'Defensible Space,' still seem to be appropriate design features that can be incorporated when new housing is being built, with little if any additional cost. These innovations can at least make the housing more attractive and livable. However, issues of whether to alter existing housing or neighborhoods must be considered in the context of determining how to allocate scarce resources. Neighbors can be allies and benefit from measures that make it easier to see who comes and goes from each other's houses. However, if neighbors are potential burglars, these measures may make matters worse.