Saturday's huge demo in Berlin against Germany's coronavirus measures has raked up a new debate about the boundaries between the right to assemble and the protection of public health.

Inevitably, given that the organizers of the "Day of Freedom" were arguing that the German government was wilfully overestimating the threat of the coronavirus, most of the 17,000 – 20,000 protesters made no attempt to wear face masks or stick to social distancing guidelines.

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That was why the Berlin police eventually disbanded the main demo, as it did many of the counter-demos also staged on Saturday. All in all, Saturday's various protests were largely peaceful, even though, according to police, isolated incidents did result in injuries to some 45 officers during the day.

By Monday, several German politicians had taken to their favored media outlets to condemn the demonstrators. Federal Justice Minister Christine Lambrecht told the Süddeutsche Zeitung newspaper that she "lacked all understanding" for those who thought themselves above the social distancing guidelines, though she was quick to add that the right to assembly was "an especially valuable legal right."

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"Annoying is too small a word," Berlin Mayor Michael Müller appeared on local public broadcaster RBB to say. "They come from Frankfurt and Stuttgart to rampage in our city. They get a demonstration right on the basis of hygiene rules that they ignore. And the worst is they simply don't recognize the facts and risk the health of other people."

But Müller and the Berlin authorities did not escape criticism themselves. In Germany, it's up to local authorities to make the conditions under which demonstrations are permitted — though their hands are tied to a great extent by the German constitution, which enshrines the right to demonstrate except when demos turn violent, if participants are carrying weapons, or if their faces are covered (which of course raises its own legal headache in the coronavirus age).

A complex problem

Still, applications need to be filed to the police at least 48 hours in advance, mainly so the police can close roads and ensure public safety. And the German Association of Towns and Municipalities (DStGB) said that Müller's government should have set stricter rules on Saturday.

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One could certainly have considered whether a limitation on the number of participants might have been possible," DStGB spokesman Alexander Handschuh told DW. "If it is no longer possible to enforce the current regulations because of the number of people, it should be possible to limit the numbers."

Handschuh also suggested that Berlin should have considered carrying out spot-checks to limit the number of people gathering in one place.

But, as Handschuh conceded, none of these measures are without their own legal problems, and the coronavirus outbreak has created new challenges for authorities.

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Paulina Starski, a senior research fellow at the Max Planck Institute for Comparative Public Law and International Law in Heidelberg, explained that the authorities can only shut down demonstrations if there's a direct danger to public security — which can include a threat to the constitutional rights of others or the legal order itself.

During the demonstration, it falls to the local police to make that judgment. In other words, the state police president has to decide whether the protest is threatening the police's ability to enforce the law.

The special conditions of a virus

Of course, among the rules the police currently has to enforce are social distancing guidelines — so there are dangers to public security inherent during the outbreak of a highly contagious virus.

"Yes, you can say that, because the police must ensure the enforceability of the legal order," said Starski. "Plus, the demonstration organizers have to consider the physical safety of others, so you can certainly argue that in the case of a pandemic."

The courts, meanwhile, have a duty to guard against constitutional violations, and, as Starski explained, will often side with people's rights rather than the police if there is doubt — partly a lesson learned during Germany's dark authoritarian past.

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As Starski added, there is certainly a danger that authorities could use coronavirus prevention measures to curtail constitutional freedoms. "Absolutely," she said. "The new rules during the hard lockdown led to a situation where the freedom of assembly was to a large extent de facto suspended — but subsequent court decisions allowing demonstrations have redressed that balance since then."

"It's a basic problem of the coronavirus situation that many constitutional lawyers are discussing because there was a massive political need to act to protect the health of the population," she added. "Now we're in a kind of review phase — are there any constitutional guidelines that need to be followed? Because from a constitutional point of view, the tendency is always towards protecting freedom."