When does photography become voyeurism? When do we, the onlookers, become voyeurs? The new exhibition at Paris’ Museum of Modern Art forces you to question yourself and, above all, the photographer. The retrospective ‘Kiss the Past Hello’ examines the 40 year career of the US photographer Larry Clark – also a filmmaker best known for the 1995 movie Kids which caused massive scandal for its raw portrayal of teenagers, sex and drugs. The exhibition features 200 images focusing on the lives of American teenagers between 1960 and 2010. From skateboarding to punk rock to drugs, firearms, suicide and sex, for four decades 67 year old Clark has made a name for himself for his uncompromising look at what goes on among our youth. In the photos they have sex, explore their bodies and take drugs, often in the most shocking way. In one shot a pregnant woman injects drugs into her arm as she sits half naked on a chair. In another a teenager bends over for a close up of her genitals. Penetration, masturbation, erection after erection - the photographs are addictive, compelling, but also aggressively uncomfortable. And this objection to the extreme graphicness of the photos is something that Paris’ town hall and I agree on. Well, sort of. For the first time in France, they’ve decided to censor the exhibition. If Larry Clark's adolescent subjects showed up in Paris to see his work, they wouldn’t be allowed in because viewings are restricted to the over 18s. It puts Paris's reputation as a home of artistic liberation into question.