This paper investigates the implications of the federal government's proposed internet filtering system in the light of Australia's blanket prohibition on 'child pornography' (including cartoons, animation, drawings, digitally manipulated photographs and text) for Australian fan communities of ACG and slash. ACG/slash fan groups in Australia and elsewhere routinely consume, produce and disseminate material containing 'prohibited content' (i.e. featuring fictitious 'under-age' characters in violent and sexual scenarios). Moreover, a large proportion of the fans producing and trading in these images are themselves 'under age'. Focusing specifically on the overwhelmingly female fandom surrounding the Japanese Boys' Love (BL) manga, the paper argues that legislators have misrecognised the nature and scope of these online communities. It is also argued that the sheer scale of this kind of material, and the fact that it is legal to download and purchase in jurisdictions such as the United States and Japan, make attempts to prohibit access to these purely fictional depictions in Australia unworkable.