Why Rihanna, Kim K & Cara Delevingne Are Tweeting #FreeCyntoiaBrown

Sex trafficking victim Cyntoia Brown, now 29, was only 16 when she was sentenced to 51 years in prison for the first-degree murder of her abuser.

In 2011, Dan Birman released the documentary Me Facing Life: Cyntoia's Story, which provided heartbreaking details about Brown's life both before and after she was trafficked.

Six years after the documentary aired, her story has caught the attention of celebrities and the general public — and many people are furious that a child was given such a lengthy prison sentence under these circumstances.

The #FreeCyntoiaBrown hashtag has quickly gone viral on Twitter and Instagram, with high-profile celebrities from Rihanna to Kim Kardashian West expressing their support for Brown. The majority of the posts include a photo of Brown during her trial, which is a powerful reminder that she truly was just a child when she was her sentence was handed down.

Meanwhile, a petition on MoveOn.org for Brown to receive a presidential pardon has gained major traction over the past 24 hours. Although it was launched in 2013, public interest in the case was revived when Fox 17 ran a new segment with an update on Brown's case, and it caught the attention of celebs like Rihanna and West. The petition currently has nearly 140,000 signatures and 75,000 of those came within the last 24 hours, a spokesperson told Refinery29 via email.

In the years since Brown was sentenced to 51 years in prison, state laws have changed. If she was arrested today, Brown would be recognised as a victim of human trafficking. During her time in prison, Brown has completed her associate's degree and is currently working on her B.A., according to Newsweek. She also works with the Juvenile Justice system.

You can sign the MoveOn.org petition here.

Cyntoia Brown was 16 when she received a prison sentence of 51 years for first-degree murder. Under Tennessee law, children convicted of this crime are required to serve at least that many years before they can be eligible for parole. Dan Birman, who produced the documentary Me Facing Life: Cyntoia's Story, argues in an article for The Conversation that punishments like these are too harsh.

Brown was a sex trafficking victim who was being sexually abused by the man she was living with. After he ordered her to go get money, she left, and a man named Johnny Allen took her home with him. She claimed she found guns in his house and was afraid he would kill her, so she shot him first, according to The Associated Press. (Prosecutors argued that she shot him to steal from him.)

After spending time with Brown, Birman believes her side of the story. Her family had a history of sexual abuse, and she was "a young runaway caught up in a bad situation," he wrote. He also believes that her case illustrates a larger problem: Due to Tennessee's laws, children convicted of first-degree murder there have virtually no shot at getting out of prison. The average life span of a prisoner is 50 years, he points out, and she'd be 67 before she could be eligible for parole. As of June 2016, 183 people serving life sentences in Tennessee had been sentenced as teens, according to The Tennessean.

Since kids' brains aren't totally developed, many consider it unfair for people's actions as children to determine the rest of their lives. This is one reason why the Supreme Court has ruled that children can't get the death penalty and states can't make life sentences without parole for juveniles mandatory. It's also why many states require reevaluations of children's life sentences after a certain time period.

With a chance at getting out, Birman believes people sentenced as teens could turn their lives around. Brown herself has gotten an associate's degree, is a mentor to other girls in her prison, and "has been called a model prisoner," according to The Tennessean.

"In my opinion, Cyntoia Brown is not the same girl who was arrested in 2004," Birman wrote. "We learned that some children – not all – do change. But even though there are systems in place to effectively rehabilitate a juvenile in the prison system, there is no hope under current Tennessee law unless this changes."