Nassib Nicholas Thaleb defines the “black swan” as the occurrence of a highly improbable
event, the equivalent of the nonoccurrence of a highly probable one. In these times of crisis
caused by the unexpected Covid-19 pandemic, a question of Thaleb appears to be of great
interest to legal scholars: «Isn’t it strange to see an event happening precisely because it was
not supposed to happen? What kind of defense do we have against that?». Without a doubt, it is not possible to give a reliable answer to this question. However, we can
ask ourselves what value indicators have from a legal point of view, and whether they can affect constitutional rights or freedoms. We can recall, in this regard, that the Italian government, based on 12 indicators, has established, for example, limitations on the right of free movement of people to counter the spread of the infection from Covid-19.
