An eco-justice perspective refers to the broad orientation of green criminology which is largely directed at exposing different instances of substantive social and environmental injustice. From an eco-justice perspective, environmental harm is best seen in terms of justice, which in turn is based upon notions of human, ecological and animal rights and of broad egalitarian principles. A key issue is the weighing up of different kinds of harm and violation of rights, that may involve stretching the boundaries of conventional criminology to include other kinds of harms than those already deemed to be illegal.