Social cleansing (Spanish: limpieza social) is social group-based killing that consists of the elimination of members of society who are considered "undesirable", including, but not limited to, the homeless, criminals, street children, the elderly, the disabled. This phenomenon is caused by a combination of economic and social factors, but killings are notably present in regions with high levels of poverty and disparities of wealth. Perpetrators are usually of the same community as the victims and they are often motivated by the idea that the victims are a drain on the resources of society. Efforts by national and local governments to stop these killings have been largely ineffective. The government and police forces are often involved in the killings, especially in South America.