One man’s punishment becomes a message to thousands when it is public, politically understandable and the limits of the next punishment are not clear. People see that someone has lost their job, freedom, income or reputation after criticism and do not have to wait for a personal threat to assess their own risk.

They begin to avoid the topic, organization or even contact with the punished person, which expands its isolation. Uncertainty often enhances the effect: if no one knows what exactly is “too much”, many withdraw much further than the authorities specifically asked. Nevertheless, silence is difficult to measure and people can withdraw for other reasons. The best evidence combines the order of events, comparison of affected and unaffected groups, surveys and concrete changes.