These 21 brave women could be arrested for sharing these photos.

In 2013, Masih Alinejad took a selfie and posted it on Facebook.

At first glance, this might not sound revolutionary. But for the Iranian-born journalist, it was a powerful act of political protest because she showed off her flowing, curly hair in the photo.

“Women in Iran are breaking the law every day just to be ourselves,” she explained in an interview with the New York Times. “And I’m a master criminal because the government thinks I have too much hair, too much voice, and I am too much of a woman.”

Masih Alinejad at the Women in the World Summit. Photo by Jemal Countess/Getty Images.

In Iran, women have to wear hijab head coverings in public, and they can be punished harshly if they don't.

But as Alinejad explained, many Iranian women also know how to steal small moments of stealthy freedom for themselves, moments when they’re hidden from the prying eyes of the piety police and are free to look the way they want.

After her selfie, Alinejad launched My Stealthy Freedom, an online movement encouraging other women to defy oppressive laws through the rebellious act of ... sharing photos of themselves.

Within 10 days, she had a Facebook following of more than 130,000 people. Just over a year later, Alinejad received the women’s rights award from the Geneva Summit for Human Rights and Democracy for her revolutionary campaign.

As of 2016, My Stealthy Freedom has built a fanbase of more than a million people, all of whom follow and engage with the selfies and stories of different Iranian and Muslim women every day. Every photo is its own small act of serious insurrection.

Photo by Mohammed Abed/AFP/Getty Images.

To celebrate, here are 21 photos of beautiful, courageous, and revolutionary Iranian and Muslim women rebelling against that compulsory hijab:

1. "To those who say I should leave the country if I don't want to wear the hijab, I say the hijab wasn't my choice. I want to have freedom in my country."

All images and quotes courtesy of My Stealthy Freedom/Facebook, used with permission.

2. "Blowing of the wind through their hair is my nation's girl's dream."

3. "I have always dreamed, and still do, that Iran would become a free Iran. Free so that all of us, especially women, can dress however they please and are comfortable with and be able to leave the house, without fearing that their choice of clothing is considered a crime."

4. "This is all I can do to make my voice reach those who don't see us; or make programs against us to be shown on our own national TV. I salute knowledge and freedom."

5. "I have never neither insulted nor hurt anyone. So I asked everyone to do the same. Don't hurt me and and don't insult me. Please respect how we want to live."

6. "Don't be surprised if you see a girl who is tempted to escape from this cruel, nonsense obligations that have come out of your mind. The air is hers as well."

7. "These are all our rights; no difference whether we are women or men."

8. "In my country, sleeping is the only time to feel real freedom, 'cause there's no rules in dreaming."

9. "I loathe the hijab. I too like my hair to feel the sun and the wind to touch my hair. Is this a big sin?"

Of course, there are also women who do wear the hijab and who are also participating in the movement to show it's the individual choice that really matters.

“I have no intention whatsoever to encourage people to defy the forced hijab or stand up against it,” Alinejad said in an interview with The Guardian. “I just want to give voice to thousands and thousands of Iranian women who think they have no platform to have their say.”

10. "I believe in hijab but hate obligatory hijab!"

11. "Here is me and my best friend in Isfahan and this is freedom of choice."

12. "Hijab is a choice, not an obligation."

It's not just a youth movement, either. Older women are also sharing their stealth freedoms.

13. "Third World is where the greatest girlish dream is the feeling of the blowing wind through their hair."

14. "Mother and daughter, Beautiful Beach."

15. "As I got out of the car a strong wind began to blow and disheveled my hair. I got angry at first and tried to tidy it up; then I said to myself, 'Don’t be a fool! This is the wind you have dreamed of, it's blowing through your hair all your life!'"

16. "This is the voice of a girl, whose dream is not dead-ended. The fence of your thought doesn't fit me."

Some women even shared photos of themselves posing with their husbands or fathers — because there are plenty of men who support these women's rights to choose hijab or not.

In an interview with Vice News, Alinejad added, "Compulsory hijab affects those women who believe in hijab, and those men who are not forced to wear hijab. ... It's an insult to men because it says men can not control themselves."

17. "This place is the tomb of Saadi in Shiraz, a very crowded place. I took this photo to show my support for freedom of clothing for all Iranian women."

18. "Justice means that my share of freedom would be the same as my husband's."

19. "I wish I could have kissed you ... here, right in this photo."

20. "We don't want a lot. Just let us be the way we are. By the way, if you look at the blue van which is parked by the road, you'll notice our risk."

21. "My father was a religious man. He said all of his prayers and fasted. He had also gone for Hajj. But he never even made his children say their prayers or fast during Ramadan; let alone forcing them to wear the hijab."

If these don't strike you as the most audacious form of defiance, just remember: Every single one of these women could be arrested for posting these selfies.

"Social media is a tool and weapon for Iranian people who have been censored for more than 30 years," Alinejad said in an interview with Vice.

"The government of Iran has guns, bullets, prisons, and power, but the people of Iran have Facebook, Twitter, Instagram, social media, and their own words."

That's why a campaign like My Stealthy Freedom is so important, perhaps now more than ever — because sometimes even something as simple as a selfie can be a tool for empowerment.