Looking at the photos, one could mistake the sea of lights in Budapest for a festive holiday event. The people who gathered in Hungary's capital Sunday night weren't holding candles, however, but smartphones. And their message is political, not religious.

They are demanding Prime Minister Viktor Orban take back a law that allows companies to ask their employees to work 400 hours overtime per year. Since the measure was passed in parliament last Wednesday, more and more people have been protesting what has been called a "slave law." In some cases, the rallies were overshadowed by violence.

The protests on Sunday started off peaceful, but police later resorted to teargas again. With around 10,000 or even 15,000 participants, Sunday's rally was the biggest event so far in a series of protests the likes of which Hungary hasn't seen during Orban's eight years in power.

France is experiencing similar unrest with the "yellow vest" protests. Is the climate in Europe's streets growing more heated?

Hungary: 'Get lost, Orban'

Many protester chants made clear that the frustration is about more than the overtime law or their premier's social policies. Under Orban, employees have lost more and more rights while the position of company managers has been strengthened.

There is also anger over Orban's actions against homeless people and migrants, and his rescue operation for Macedonian ex-Prime Minister Nikola Gruevski, who was sentenced to prison in his home country.

Serbia: Against state violence

In Serbia's capital, Belgrade, thousands of people took to the streets again this weekend. Many of them voiced their anger at the government with whistles and horns, as they did during the mass protests against the Milosevic regime during the 1990s.

The trigger for the current protests was a brutal attack on the head of the Serbian Left party, Borko Stefanovic. In late November, men in black shirts beat the politician with an iron bar in the southern Serbian town of Krusevac, leaving him seriously injured. President Aleksandar Vucic condemned the attack and the perpetrators were caught, but the opposition continues to blame Vucic's harsh rhetoric for a climate of violence in the country.

Albania: More than high tuition fees

In Albania, students have been calling for lower tuition fees since the beginning of December. Tuition at state universities is between €160 and €2,560 annually ($180 and $2,900), while the average income in the poor Balkan country is only €350 per month. Protesters in the capital, Tirana, and other Albanian cities are increasingly concerned with the government of Prime Minister Edi Rama in general. They used roadblocks, among other things, to draw attention to the country's widespread poverty and high petrol prices.

France: What will happen with the 'yellow vests?'

Roadblocks due to high petrol prices — that's how the protests by the "Gilets Jaunes," or "yellow vests," began a few weeks ago in France. The massive, nationwide protest has lost some of its momentum following President Emmanuel Macron's concessions and the Strasbourg attack. The scale of the protests in Paris last weekend was a lot smaller than in previous weeks.

The billion-dollar emergency program Macron presented, which includes a €100 increase of the minimum wage, is putting France in budget difficulties: In 2019, Paris is likely to rack up more debt than the Euro Stability Pact stipulates.

Read more: France's 'yellow vests' and the Russian trolls that encourage them

The "yellow vests" have achieved their original main goal of preventing the eco-tax on fossil fuels. However, the movement has ignited a serious societal debate in the few weeks of its existence, while at the same time growing strongly on both ends of the political spectrum. This rapid growth could be the death of the movement if the goals of the participants diverge to such an extent that they can no longer agree on a common agenda.

Europe united in protest?

"One could assume that this symbol of the yellow vest can be transferred very quickly, because everyone has one in the car," protest researcher Sabrina Zajak told DW recently, referring to the yellow safety vests donned by protesters in France. "And there is of course dissatisfaction in many other European countries."

Read more: Emmanuel Macron and the 'yellow vests': Can they cooperate?

But it appears at this point as though the protests will not spread on a grand scale. After sporadic sightings of "yellow vests" in Belgium and the Netherlands, German Left Party politician Sahra Wagenknecht's Aufstehen (Stand Up) movement called for a yellow vest rally in Munich at the weekend. According to German police, only 100 people participated in the demonstration. Aufstehen said there were 200 participants.

So far Zajak's assessment has been confirmed. "The protest in France has something to do with the very specific country context," he said.

The protests in Eastern Europe are also specifically directed against local governments.

"A European protest movement is more likely to occur when transnational concerns like professional livelihoods are at stake — with fishermen, winegrowers or farmers," sociologist Dieter Rucht told German public broadcaster ZDF. "But what you do see almost everywhere in Europe is a rising level of resentment and anxiety."

Read more: 'Yellow vest' movement: How artists see it

While social and labor market policy are national issues, global warming doesn't stop at any border. Accordingly, there is at least one small protest movement that is becoming more and more European.

The "school strike for climate" in the summer was initially a solo event organized by 15-year-old Swede Greta Thunberg. But ever since her speech at the climate conference in Katowice, a growing number of students in several European countries are participating. Last Friday, hundreds, perhaps thousands of students took part in Berlin, Hamburg, Munich, Cologne, Kiel, Göttingen and other German cities.