The meaning of “conspiracy theory” constantly contracts and expands. On one hand, the phrase is regularly used to describe fringe views that do not involve alleged conspiracies. On the other hand, people tend to avoid using the phrase when describing conspiracy claims embraced by the mainstream, even when those ideas are highly dubious. Popular narratives about terrorism, gang activity, and new religious movements resemble more marginal conspiracy theories, particularly when they confuse decentralized networks with centralized organizations, perceive plots that don’t exist at all, or draw on the lurid imagery of pulp fiction.