The damaging social side-effects of America's so-called war on drugs come under scrutiny in this documentary from director Eugene Jarecki. Constructed from street-level reportage, expert testimony and startling statistics, it reveals a system in crisis. Punitive prison sentences intended to deter narcotics users and dealers have resulted in the world's largest number of inmates per head of population. This may be good news for the private firms that run the penal institutions, but it's having a destructive effect on the black community: it's estimated there are more African-Americans behind bars today than there were in slavery before the US Civil War. There are effective arguments here, since the film canvasses opinion from dealers, prisoners, cops and correctional officers, who all agree the present situation cannot continue. Less convincing however, is Jarecki's somewhat self-conscious attempt to relate all this to his own family experience, resulting in a contentious - and not entirely persuasive - comparison between the war on drugs and the Holocaust. This is an impassioned and provocative offering but ultimately it doesn't quite hang together.