A string of at least 69 arrests in France this week on the vague charge of “defending terrorism” (“l’apologie du terrorisme”) risks violating freedom of expression, Amnesty International said.

All the arrests appear to be on the basis of statements made in the aftermath of the deadly attacks against the magazine Charlie Hebdo, a kosher supermarket and security forces in Paris on 7 and 9 January.

“In a week in which world leaders and millions around the world have spoken out in defence of freedom of expression, the French authorities must be careful not to violate this right themselves,” said John Dalhuisen, Europe and Central Asia Programme Director at Amnesty International.

“How the French authorities act in the aftermath of the horrific killings is the litmus test for its commitment to human rights for all.”

The arrests and prosecutions are the first to be carried out under the new November 2014 counterterrorism law. They are based on a criminal code article under which “inciting” or “defending” terrorism carries a sentence of up to five years in prison and a fine of EUR 45,000, and up to seven years and a EUR 100,000 fine if it involved posting something online.

While “incitement” and “defence of terrorism” were already offences in France, the November 2014 law moved them from the press law to the criminal code. This means the process can be fast-tracked by the authorities, which has happened in several of this week’s cases.

Besides the highly publicized case of comedian Dieudonné M’bala M’bala, examples of cases include a man shouting in the street “I am proud to be a Muslim, I do not like Charlie, they were right to do that”, as well as an intoxicated man who, upon his arrest for drunk driving, allegedly told the police “there should be more Kouachi; I hope you will be next.”

Another case involves a 21-year-old who was caught without a ticket on a tram, and subsequently sentenced to 10 months in prison for allegedly saying, “The Kouachi brothers is just the beginning; I should have been with them to kill more people.”

A number of cases have already been prosecuted and led to convictions under an expedited procedure.

The arrests, investigations and convictions follow a circular issued on Monday 12 January in which Minister of Justice Christiane Taubira instructed prosecutors that “words or wrongdoing, hatred or contempt, uttered or committed against someone because of their religion must be fought and pursued with great vigour”.

Governments have an obligation under international human rights law to prohibit advocacy of national, racial or religious hatred that constitutes incitement to discrimination, hostility or violence. But vaguely-defined offences such as “defence of terrorism” risk criminalizing statements or other forms of expression which, while undoubtedly offensive to many, fall well short of inciting others to violence or discrimination.

International treaties on the prevention of terrorism require criminalization of incitement to commit a terrorist offence. However, there is a risk that notions such as "defence of terrorism” will be used to criminalize statements made without the necessary element of intent and the direct and immediate likelihood that they would prompt such violence.

Some of the recently reported cases in France may cross the high threshold of expression that can legitimately be prosecuted. Others, however offensive the statements made, do not.

“Freedom of expression does not have favourites. Now is not the time for knee-jerk prosecutions, but measured responses that protect lives and respect the rights of all,” said John Dalhuisen.