Beeban Kidron's quietly alarming investigation of the bowels of the internet (we open, significantly, in a sewer) moves from the testimony of teens addicted to online porn to a wider examination of information ownership and market-driven manipulation.

While the creeping surveillance narrative is well rehearsed (Julian Assange pops up to do his party piece), Kidron opens up a wide range of debates in which we all need to be involved. It's unsettling viewing, and smartly sidesteps allegations of parental paranoia by talking directly to those "digital natives" whose lives are being transformed (for better and worse) by the web.