Illicit drug policy is at a time of flux. The last few years have seen the first legally regulated cannabis markets in the United States (Pardo, 2014; Room, 2014). There has been an increasing concern about the rise of new synthetic drugs – commonly referred to as new psychoactive substances (NPS) – drugs that mimic the effects and/or chemical structure of illicit psychoactive drugs such as cannabis and ecstasy (Griffiths et al., 2013). There is concern that new technologies (such as the internet) are profoundly changing drug markets and the ways in which drugs are purchased and consumed (Barratt and Lenton, 2013). Misuse of legal drugs, especially pharmaceutical opioids, is a rising issue (Executive Office of the President ...