The photo that sparked a movement is unassuming: Masih Alinejad sits behind the wheel of her car, sunglasses on, a scarf tied around her neck, smiling broadly. Being in public without a head covering—or hijab—could have landed Alinejad in jail in her homeland of Iran. In publicizing that unmasked moment, what Alinejad calls a “guilty pleasure, she has sparked an online revolution for thousands of Iranian women sick of the the government demanding they cover up.

On May 1, Alinejad posted her scarf-less picture on Facebook, hashtagging it #mystealthyfreedom. “Hijab is being forced on women not only by the Morality Police,” she wrote in the caption of Iran’s religious patrols, “but also out of consideration for family, through wanting to keep a job and because of fear of judgment from others.”

Did any other women wish to share a moment of stealth freedom? she asked. They did—before long it wasn’t just likes, comments, and shares piling on, but women were posting their own bare-headed pictures. “I was sure that most Iranian women who don’t believe in the forced hijab have enjoyed freedom in secret,” she says.

The response, she says now, “was staggering.” Two days later she built a Facebook page to serve as a home for the movement and to post submissions from Iranian women. Membership bumped by tens of thousands each day. Now, 230,000 people have gotten behind Alinejad’s crusade of bareheaded subversion.

“It is clear from the response that Iranian women wanted to express themselves and voice their opposition to the compulsory hijab,” Alinejad says. In Iran, going out without a head covering risks detention by patrols of morality police and punishment of lashes and two months jail time. Facebook is also banned, but widely used.

“I am delighted to have been able to offer a platform for Iranian women to ‘let their hair down,’” she says.

It turns out women have been loosening their scarves throughout Iran, from Persepolis to Tehran, while standing in the bustle of a city or the solitude of the ocean or a sandy desert dune. Supportive comments under each photo number in the hundreds, with messages of encouragement streaming in from Norway, Azerbaijan, Texas.

“It had been the very fist [sic] time I had ever seen the desert. As sun was rising in order to respect her beauty, I took my headscarf off so that she could see me beautiful too . That feeling was great.. I was..fearless in the desert,” one woman, with her face upturned against a background of sand, writes.

One brave woman unwound her red scarf and posed with her fingers making the peace sign in front of a billboard in front of the office of Iran’s Ayatollah Khamenei. Her message, translated into English, reads:

“we will move faster and fastertill u understand what we are capable of doingwhatever you say we MUST NOT do, we will do!Hoping for freedom”

Alinejad says her inbox is stuffed with submissions—more than a thousand currently—which she goes through and verifies before posting. The notes she receives stress the feeling of being unchained, free, and having wind blown through their hair. On Wednesday, Alinjejad was proud to share that noted human-rights lawyer Nasrin Sotoudeh had written in to the campaign describing an incident during her three years in jail when she refused to wear the full-body-covering chador.

“I told my jailers that I am not wearing the chador anymore and I'd rather they chopped off my head right in front of the warden's office door,” she remembers.

The movement’s name, Sotoudeh adds, was “rather an ironic term to refer to the current surge of activity that is going on in Iran. Because, as we all know, if something is done stealthily, then it cannot be called FREEDOM. The term "Stealthy Freedom" is indicative of the pressures that exists within Iran.”

Men have also written in to the page, offering words of support and even taking responsibility for the lack of women’s rights. “I owe you all an apology,” one writes. “I apologize to all of you who dance and laugh stealthily and whose freedom has to be stealth. I owe you all an apology for ruining even your stealth moments of freedom by my looks or words.”

Alinjejad is already being bashed and called an anti-revolutionary in conservative Iranian media, she says, and by a hardline movement petitioning for stricter enforcement of modesty laws that are sometimes lax in metropolitan areas. Last week, 500 demonstrators gathered in Tehran to protest against immorality.

“[The] hijab is about control,” Alinjejad says. And the “Iranian regime would never want to lose control.

On Friday, Alinejad’s #mystealthyfreedom campaign was called out by the prayer leader in Tehran: “In certain towns and cities, some [women] have been seen to have removed their Headscarves. This lack of hijab has infiltrated homes via internet and satellite TV,” he said according to Alinejad’s translation. He called for support, saying, “we are Muslims and must help girls and youth so that they do not sin.”

“I am not unfamiliar with ‘backlash,’” Alinejad says. An outspoken Iranian journalist, she had been covering the parliament when she was forced to leave during the contentious 2009 elections. Alinejad says that in her work she had been imprisoned, physically attacked, and the victim of a smear campaign. She’s now based in London and says if she returns to Iran she faces jail time.

Freeing her hair from its covering hasn’t been easy for her either. Alinejad’s personal Facebook is filled with photos of her sans hijab, her curly hair running in tight curls past her shoulders, piled atop her head, and laced with flowers. It’s clearly a point of pride and subversion, inspiring tens of thousands of likes and endless threads of comments from her 213,000 followers.

But as she told the Guardian last year, her father has stopped speaking to her after the government printed some of the unveiled Facebook pictures and spread them through her family’s small village. “They are afraid of our freedoms in the West and fear women in Iran could see that and demand the same," she said then.

Now, it appears she has inspired such a campaign even from exile.