Cannabis liberalization is a fascinating case study in moral-legal re-negotiation. From broad international examples of decriminalization to specific local legalization models, numerous criminological questions are emerging. This paper describes three significant challenges for cannabis liberalization. These include persistent inequalities associated with policing cannabis, the invisibility of coercive care and control within diversion, and the hazards associated with illusory policy reform. We present Cannabis Criminology as a multidisciplinary effort to understand the prohibition, decriminalization, legalization, and nascent regulation of cannabis in ways that acknowledge but transcend law-based paradigms. Consistent with criminology's multiple and sometimes contradictory dimensions, we outline five thematic areas that can inform the study of cannabis. These include law, society, and social control, police and policing cannabis, race, ethnicity and intrusion, the economics of cannabis use, and cannabis and criminal behavior. Finally, we conclude that privileging the views of people who use cannabis can provoke more inclusive, participatory, and otherwise imaginative efforts. [ABSTRACT FROM AUTHOR]