The fear of conspiracies led the Roman government to drastic action that included use of slave informers (thus overcoming another deep-seated fear), mass execution of citizens, and even execution without trial.

Over the course of the first half of the second century B.C.E. there was a series of at least four mass trials of Roman matrons charged with poisoning. Little is known of the details, but it is virtually certain that these were "witch-hunts" rather than the reflection of waves of poisoning. This is a stereotypical conspiracy story in at least two respects. Wives were supposedly murdering their husbands—the ultimate betrayal from within. Poisoning was appropriate both because it is inherently sneaky and because in primitive technological circumstances it can never be disproved: Any woman whose husband died of illness or natural causes could be suspect...