Documentary film has evolved significantly since its origins in the early 1920s. Early documentaries like Nanook of the North took a creative, poetic approach to interpreting reality. The direct cinema movement of the 1950s-1960s brought social and economic issues to mass audiences in a direct, unmediated style enabled by advances in portable camera technology. Similarly, cinema verite documentaries in France at this time aimed to minimally involve filmmakers and rely solely on subjects and events. Modern documentaries, aided by widespread DVD distribution, have become hugely popular and profitable vehicles for broadcasting opinions on issues like global warming to large audiences. More recently, mockumentaries have adopted documentary techniques and conventions to stage fictional stories as though they were real footage