The warnings are delivered as phone calls and texts. The sender always flashes up as unknown. But the messages are clear: “We have seen you in the protests. If we see you again, there will be trouble. This is your first and last warning.”

Three weeks after demonstrations erupted across Iran following the funeral of Mahsa Amini, 22, who died after being arrested for her “inappropriate dress”, the threats keep coming.

The caller usually identifies themselves as a member of Iran’s feared Intelligence Organization of the Islamic Revolutionary Guard Corps. Then they reveal details of the victim’s life to add a sinister touch: the name of the street where someone was spotted; a home address; a route to work.

Iranian state television broadcasts videos of the consequences for joining the growing clamor of opposition: footage of the regime’s forces raging into battle. The front line is its citizens’ front doors and windows, smashed in with boots and batons. Men and women accused of protesting are dragged out of their homes mid-dinner and bundled into waiting vans.

Another video on Iranian TV shows footage from street CCTV cameras. A lens zooms in on the faces of women who refuse to wear the hijab (headscarf), and as a synth-heavy horror-film soundtrack reaches a crescendo, the camera picks out individual fist-pumping protesters. Again, the message is clear: we know who you are and we are coming for you.

“Woman, Life, Freedom.”

Friends in Iran tell me these intimidation tactics are having an effect. Recently, more Iranians are staying home, fearful of getting caught in the enforcers’ crosshairs.

They also reveal a slight change — panic, perhaps — in the regime’s strategy of dealing with the biggest threat to the Islamic Republic’s existence since its birth 43 years ago.

Over the past decade, protests in Iran have been happening with growing frequency. Yet the uprising that is happening now eclipses all that has come before. The regime has never been up against such widespread, broad and united dissent. All classes, socioeconomic levels and ethnicities have joined forces. They want something far bigger than economic and political reform. They are demanding freedom and regime change.

Men and women accused of protesting are dragged out of their homes mid-dinner.

Friends of my generation, mostly in their forties, have been out protesting. They have been beaten and tear-gassed and one had his hand broken. Yet they refuse to be silenced. They say they have never before witnessed this magnitude of rage and hatred for the government and its religious leaders. And yet they tell me the anger, courage and resolve of the protesters of our generation is nothing compared with that of the younger generations. It is these 20 and 30-year-olds who are leading the charge.

Iranians lit candles and held up photographs of Amini during a protest in Istanbul last month.

Born well after the revolution their parents led, they know nothing of the previous regime. These are the children of the Islamic Republic, born and bred under the watchful eyes of the mullahs. They are the revolution’s chickens coming home to roost.

Young women, hair uncovered, are squaring up to riot police, screaming in their faces: “Come and get me!” Hundreds are burning their hijabs and chopping their hair as crowds of men and women chant: “Women, life, freedom!” And: “Death to the dictator!”

Thousands more are going about their daily lives with no headscarf in sight. “We don’t just fight you during the night, we fight you in broad daylight by walking around the main streets not wearing our hijabs,” says one lipstick-wearing young woman in a self-filmed video.

The regime has never had to deal with insubordination or fearlessness on this scale from its citizens. It has found itself blindsided by seismic societal changes that have been quietly bubbling away under its watch.

The bravery of the young has been nurtured in the bedroom, where the mullahs have been unable to police the love lives of Iranians. The influence of global popular culture on Iran’s Generation Z, hungrily imbibed through social media and satellite TV, has radically shifted sexual politics. Virginity — a cornerstone of a religious patriarchy governed by strict Sharia — has lost its value among the youth.

Protesters set their scarves on fire while marching in Tehran.

So many young Iranians are cohabiting before marriage that the supreme leader’s office issued an edict declaring the practice “shameful” and ordering officials to “show no mercy”. That was seven years ago. Since then even more couples are flouting the country’s laws on sex.

Just as it has been impossible for the regime to control its citizens’ love of a good party and alcohol — which flows through the length and breadth of the country — it has been impossible to control the intimate lives of millions.

The regime’s modus operandi has been to both punish Iranians into adhering to the rules, while also appeasing them by permitting the bending of those rules. It is a cyclical model punctuated by crackdowns to keep the system in order and the population cowed.

It is these 20 and 30-year-olds who are leading the charge.

But this sexual awakening has encouraged Generation Z to seize new freedoms and quietly change the social order.

In the past year and a half, across Tehran’s streets, and even in the subway, some young women have been taking to the streets without a hejab. More and more have been refusing to wear them in cars. They risk arrest and even flogging. Such brazen disregard for the law would have been unthinkable a few years ago.

During Iran’s baking hot summers when women are less inclined to be fastidious about covering up, the morality police ramps up its operations. Mahsa Amini caught the tail end of the summer crackdown.

Her murder at the hand of the morality police has unleashed a paroxysm of hatred for Iran’s religious regime and its merciless enforcers.

So far, the regime’s reaction has been violent, but indecisive. It is being reported that at least 83 have been killed. The real number will be higher. This is still a low figure considering the numbers on the streets and the regime’s past form. The security services have not yet been ordered to unleash their full might — so far they have been mainly using metal pellets, water cannons, tear gas and batons.

An Iranian woman lifts a national flag at a pro-government rally in the Tajrish neighborhood of Tehran earlier this week.

The Iranian government is flailing. The very nature of these protests has made it difficult for the regime to react. Unlike past protests, there are no leaders to silence, no political groups to quash, no promises of economic reform to pacify them. This uprising may have started about women’s rights, but it is the accumulation of 43 years of oppression – mental, sexual, social, political and economic. The protests are everywhere, and the protesters are everyone.

The regime also knows the world is watching. And it may fear that too many killings at this point will only inflame the protesters.

Already the morality police have been withdrawn from the streets, probably for their own safety. Crowds of demonstrators have fought back gangs of Islamic militiamen, known as the Basij, who have been filmed being tackled off their motorbikes and beaten. There is footage of security forces running from protesters. Police cars have been burned or overturned.

“They’re scared of us. Of us! Can you imagine such a thing?” said one friend via a WhatsApp voice note.

“When I’m out on the streets and I look around, and see thousands protesting and nobody is wearing a hijab, I feel like I’m dreaming.”

The regime is also in one of the most vulnerable phases in its history. The 83-year-old supreme leader, Ayatollah Ali Khamenei, is in ill health and while his son has reportedly been primed as his successor, the theocracy is facing a leadership crisis.

That’s good news for the uprising. With the regime’s very survival at stake, many of us fear that it will soon begin to kill in large numbers, using terror to subdue Iran’s audacious, hopeful youth. That may not be enough.

“Whatever happens now, even if there is a bloodbath, a line has been crossed,” another friend tells me. “And this time there is no turning back.”

Ramita Navai is an Emmy- and Robert F. Kennedy Award–winning British-Iranian journalist, documentary producer, and author