They come in the thousands on Monday nights to march in the eastern city of Dresden, armed with a litany of complaints – against politicians, against the media, against asylum seekers and against Muslims, whom they accuse of altering the fabric of German life.
Now Wednesday's deadly attack on a satirical newspaper in Paris threatens to further inflame a movement that is testing Germany's commitment to tolerance and openness.
The group organizing the rallies is called Patriotic Europeans Against the Islamization of the West, or PEGIDA after its German acronym. Before October, it didn't exist. But earlier this week, 18,000 people attended its weekly demonstration in Dresden.
The group claimed on Wednesday that the murders in Paris validated its views. "The Islamists … showed in France today that they are not capable of democracy," it said in a statement on its Facebook page. "Our politicians want us to believe the opposite. Must such a tragedy happen here in Germany first?"
PEGIDA marks a challenge for Germany, which has sought to overcome its history of right-wing extremism and provide a haven for refugees fleeing conflict zones. While the demonstrations have remained focused on Dresden, polls show some sympathy nationwide with the protesters as well as a large reservoir of anti-Muslim sentiment.
The demonstrations have drawn a chorus of criticism from mainstream politicians, including Chancellor Angela Merkel. Thousands of people attended a series of counterprotests against xenophobia earlier this week.
In Cologne, church leaders turned off the lights at the city's towering medieval cathedral to signal their rejection of the movement.
Despite such condemnation, experts believe the violence in France could give fresh impetus to PEGIDA, which will once again take to the streets on Monday evening. "They will have the feeling that they received a confirmation for what they argued about the dangers of Muslims in Germany," said Nico Lange, an expert on German politics at the Konrad Adenauer Foundation, a think tank in Berlin.
PEGIDA is not a political party, but its ability to mobilize thousands represents a political opportunity. The new Alternative for Germany party, a right-wing outfit hostile to the euro, has held talks with the organizers of the protests.
The protests remain centred on Dresden, but point to broader dissatisfaction in Germany. In one national poll last week, 29 per cent said the marches were justified given Islam's influence in Germany.
Meanwhile, a new study by the Bertelsmann Foundation released on Thursday found that 57 per cent of non-Muslim Germans believe that Islam is a threat, up from 53 per cent in 2012. The percentage who believes that Islam is incompatible with the Western world is even higher, at 61 per cent, a jump from 52 per cent two years earlier.
"Islamophobia has become a socially acceptable trend – despite the fact that a large majority of the population is, in general, open to religious diversity," the authors of the study wrote.
The proportion of people who viewed Islam as a threat was higher in regions of the former East Germany, even though such areas have a lower proportion of Muslims and immigrants in the overall population than in the former West Germany.
Werner Patzelt, a political scientist at the Technical University in Dresden, said the East German context is critical to understanding PEGIDA. The region has "undergone a very, very deep social, economic and cultural transformation" since the fall of the Berlin Wall in 1989, he said. Now some perceive a new wave of transformation toward a more multicultural society, a change they didn't ask for or endorse, Prof. Patzelt added.
"They feel alienated from our political system, treated arrogantly by the political class, and that policies are imposed upon them," he said. He's attended three of the protests as an observer and says many of those present have been "improperly labelled as right-wing extremists."
The group's precise aims remain vague. Its founder is a Dresden native named Lutz Bachmann, who works in advertising and has been arrested for burglary and drug possession. The group has a sprawling 19-point position paper, which includes resisting a "misogynist, violent political ideology" and preserving and protecting "our Judeo-Christian culture."
One of the protesters' favourite chants is "Wir sind das Volk" – "We are the people" – a reprise of the motto shouted by the pro-democracy demonstrators who opposed the Communist regime in East Germany. Ms. Merkel, in a new year's address to the country, wasn't amused by the historical echo. "What they actually mean is: 'You don't belong, because of the colour of your skin or your religion,'" she said.
"Migration is changing [German] society," said Andreas Zick, a migration researcher at Bielefeld University. "Now we observe that some people in society object to the change." But the shift is well entrenched. In the neighbourhood around Frankfurt's main train station, he noted, there are people hailing from over 190 different countries. "And we are still discussing if we are a multicultural society or not."