This documentary by David France persuasively argues that one of the greatest grassroots activist campaigns of modern times was the Act Up movement in the US, which demanded immediate, large-scale research into Aids treatment. The film traces its dramatic history from the early 1980s to the late 90s. Act Up directed a roar of anger against the indifference and homophobic hostility in the political establishment, some of whom simply shrugged at Aids as a plague sent by God to punish homosexuals. This was no gentle write-in campaign.

Act Up believed in direct action, boisterous demonstration and tough confrontation: to show people the lesions and the pain. The movement's occasional carnivalesque shrillness and stridency was an important, though perhaps not entirely intentional tactic. The mission was to discomfort, to upset the apple cart and to jolt everyone out of their complacency, from the politicians to the federal drug administration.

Ronald Reagan was icily opposed to more research funding, which crucially decelerated progress towards treatment: a baffled and resentful George Bush Sr found that his misreading of the Aids issue contributed to the fizzling out of his presidency.

Bill Clinton mastered the political language of progressive empathy, and his own administration was more sympathetic, but France's film argues that, interestingly, the political right was sympathetic to gay men getting alternative treatment on the entrepreneurial free market.

At any rate, nothing would have been done without Act Up pushing hard, even when it was suffering acrimonious internal splits and schisms of its own. As activist Larry Kramer remarked, the movement had "its good cops and its bad cops", and there is a remarkable, angry, passionate funeral speech from campaigner Bob Rafsky that helped mobilise Act Up and awaken America's conscience.