The Coronavirus crisis offers many points of reflection about privacy. My colleagues Anni Haahr Henriksen, Natália da Silva Perez, Natalie P. Koerner, and Natacha Klein Käfer have excellently dealt with many of them. One major issue is represented by the increasing governmental powers of surveillance. Arguing that surveillance will prevent the spread of the novel Coronavirus (COVID 19) governments are starting to use apps, drones, and other forms of technology that erode the citizen’s right to privacy.
It is not a novelty that technology is accused of going against the right to privacy. Ten years ago the founder of Facebook already stated that privacy is no longer a social norm. But now governments can use technology to control the movements of citizens. At the moment, apps and similar instruments seem to be restricted to health needs and time-limited. But what happens if governments choose to use them permanently and for other needs? For example, the police might determine whether the author of a crime was actually on the crime-scene. Public authorities might be able to know where we are and use this information in a trial (e.g. to sanction violations of the lockdown).
What happens if a piece of information about our ‘private’ life becomes public? What happens if public authorities use this information in a civil or criminal process?
These questions about the boundaries between public and private were, albeit in a different way, also discussed in the medieval and early modern period. Judges might have had to decide whether to use information obtained outside of the trial, without the observance of processual rules, to decide a case. For example, suppose that Titius has claimed that Caius owed him a large sum of money by virtue of a contract concluded in Paris. The judge knows for sure that Caius was not in Paris at that time. The evidence against Caius is therefore false. But is the judge allowed to use this information?
Strictly speaking, processual rules did not allow that. Judges were only allowed to use evidence introduced by the parties. But judges were both legally and morally responsible for pronouncing the right decision. They were not only demanded to comply with processual rules, but also to obey their conscience. They answered for their acts before God. The salvation of the soul was a deep concern and a wrong decision could send the judge’s soul to hell. The dilemma at hand, then, was whether the judge should base his decision on evidence or conscience.
The most influential Catholic theologian, Thomas Aquinas (1225-1274) famously affirmed that the judge exercises a public function and for this reason should only use his knowledge as a public person, not what he knows as a private person. Procedural order must have rigid limits and what the judge knows privately, outside of the trial, must not be used. Aquinas distinguished divine judgment (God knows the truth) from human judgments, which are regulated by processual rules and aim to processual truth.  Following the path charted by Aquinas, the Spanish Catholic jurist and theologian Diego de Covarrubias y Leyva (1512-1577) stated that a judge could lawfully pronounce a sentence on the exclusive basis of the evidence, even if this was against what he knew privately.
The great Lutheran jurist Johann Oldendorp (1486-1567) argued instead that the judge should avoid a lie. Saying something that differs from what we know is a lie. If we know that someone is innocent, we have to act accordingly. Aquinas separated a conscience formed through a man’s personal knowledge from a conscience formed according to public judgment. Oldendorp responded that the judge cannot have a double conscience. Conscience cannot be divided. A judge should draw on his conscience. Along the same lines, the Reformed theologian Markus Friederich Vendelin (1584-1652) affirmed that nobody is obliged to condemn an innocent or acquit a guilty publicly or privately (innocentem damnare et nocentem absolvere privatim vel publice, nemo tenetur). What the judge knows in private should correspond to his public decision.
Early modern theologians and jurists also brought Pontius Pilate into this debate. Pilate knew that the high priests had handed Christ over to him out of jealousy. Should he have used this (private) information and acquitted Christ? According to the famous Wittenberg theologian, Friederich Balduin (1575-1627), Pilate knew that the high priests’ accusations were false and that he had condemned an innocent to death. Some years later, Johann Steller (1641–?), a jurist from Jena, affirmed instead that Pilate should be excused because he was acting as a magistrate and therefore had to follow the accusations of the high priests. 
Conscience or evidence? The Helmstedt Lutheran theologian, Conrad Horneius (1590-1649) observed that the judge who ignores what he knows privately can be a liar and condemn an innocent to death. On the other hand, however, considering the life of a private man in a judgment could destroy processual order and lead to the dissolution of the state.  To Horneius, judicial powers should be regulated by processual rules that forbid judicial arbitrariness. These rules must have limits that safeguard private life.
Early modern scholars continued to debate this issue without providing a definitive answer. Nonetheless, their contribution can help us to reflect on the possible outcomes of the Coronavirus crisis. Overwhelming judiciary powers might sound morally promising: they might be instrumental in avoiding an unjust sentence or help to convict a criminal that otherwise would not be punished. But they can also lead to a devastating invasion of privacy. Which aspect should be prioritized? The moral necessity to pursue truth or the defense of our privacy?
Public authorities are starting to use apps that control our movements in order to prevent the spread of the novel Coronavirus. Through these apps, authorities are able to know about our location. Should this information become public or should it remain private? Should the law grant public authorities the right to use this information in a trial?
Our privacy is proportional to the powers the public authorities have to control us. An increase in their powers means a decrease in our liberty. By admitting these apps as legal means of proof, the states will build extensive surveillance systems. They will collect and use our geolocation data. On the other hand, the restriction on our liberty might also have positive effects. Digital surveillance might facilitate the repression of crimes and help judicial authorities to avoid the conviction of an innocent.
There is a tension between privacy and public morality. Privacy might prevent the public authority from pursuing the common good (in this case the public health). As such, it might be seen as a selfish right. But, then, why is it so important for us?
 James Q. Whitman, The Origins of Reasonable Doubt. Theological Roots of the Criminal Trial (Yale University Press, 2008); Wim Decock, ‘The Judge’s Conscience and the Protection of the Criminal Defendant: Moral Safeguards against Judicial Arbitrariness’ in Georges Martyn and others (eds.), From the Judge’s arbitrium to the Legality Principle (Duncker & Humblot, 2013), 69-94.
 Thomas Aquinas, Summa theologiae, IIaIIae, q. 67, a. 2.
 Judit Bellér, ‘De insontibus non condemnantis. Conflitti di coscienza del giudice nella giurisprudenza tardo-medievale’ (1991) XXI, n.2, Materiali per una storia della cultura giuridica, 299-300. Diego de Covarruvias y Leyva, Variarum ex iure pontificio regio, et caesareo resolutionum (Venetiis, 1565), lib. 1, 7-10.
 Johannes Oldendorp, De iure et aequitate disputatio forensis (Francofurti, 1611), 137–138.
 Thomas Aquinas, Summa theologiae, IIaIIae, q. 67, a. 2.
 Markus Friederich Vendelin, Philosophia moralis, (Hardervici, 1654), 685.
 Friederich Balduin, Tractatus de casibus conscientiae (Wittenbergae, 1628), 1174.
 Johann Steller, Defensus Pontius Pilatus (Dresdae, 1674), tertium caput nn. 92–100.
 Conrad Horneius, Philosophiae moralis sive civilis doctrinae de moribus libri IV (Francofurti, 1633), 629.