Welcome to the documentary from the BBC World Service.

I'm Rahak Ansara, a reporter for BBC Trending, which delves into the world of social media.

Today, we're looking at Iran.

A word of warning before we start, this episode includes

some very distressing accounts of violence which Iranian women have endured at

the hands of the authorities. For security reasons, we've kept some details vague.

The testimony you're about to hear is voiced by an actor

and we've changed her name to protect her identity.

That day I went out.

I put my medication on my ID in my bag and left despite the risk.

I said to myself, I'll go out even if they arrest me.

Last year, Aleph was arrested after a photo she posted online was picked up by the Iranian authorities.

I didn't really care enough to hide who I am or where the photo was taken. I wanted to say we exist.

Aleph had taken off her headscarf, known as the hijab, unwrapped it from her neck, and walked the streets of Iran's capital to Iran.

Why did I do that? Because I needed an outlet for all my pent-up emotions to share them with people who thought like me.

In a country where the internet and social media is heavily regulated and surveilled,

walking in public without a hijab and then documenting it for social media

was seen as an act of defiance.

But why now?

The morality police was always out on the streets checking our outfits.

If we didn't meet their expectations we could expect anything from verbal warnings to violence.

They would attack women on sidewalks, drag them into vans. We witnessed

...