This turns out to be true in cases where there are collapses in consensus that have serious societal consequences. Whether in relation to climate change, GM crops or the UK's triple vaccine for measles, mumps and rubella, alternative science networks develop amongst people who are neither ignorant nor irrational, but have perceptions about science, the scientific literature and its implications that differ from those prevailing in the scientific community. These perceptions and discussions may be half-baked, but are no less powerful for all that, and carry influence on the internet and in the media. Researchers and governments haven't yet learned how to respond to such "citizen's science". Should they stop explaining and engaging? No. But they need also to understand better the influences at work within such networks — often too dismissively stereotyped — at an early stage in the debate in order to counter bad science and minimize the impacts of falsehoods.