If you’ve logged into Facebook today, you might have noticed – amidst the baby photos and long-winded status updates about Donald Trump – a smattering of mysterious red X’s. The reason? Slavery.

People are changing their profile picture to an image of a red cross for ‘Shine a Light on Slavery Day’, an initiative from the End It Movement. Celebrities including anti-slavery campaigner Ashton Kutcher, members of US Congress and others are all expected to take part, Refinery29 reports.

The charity campaign, now in its fifth year, is focused on raising awareness of the issue of modern-day slavery and human trafficking. It’s all too easy to think of slavery as a horror from a time gone by, but for millions of men, women and children, it’s very much a part of life in 2017.

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Precise statistics on how many people are currently enslaved around the world are hard to verify, thanks largely to the crime’s inherently hidden nature. However, there is thought to be a huge gulf between the number of people living in forced servitude and the number of those identified by services as in need of help.

Almost 21 million people worldwide are estimated to be victims of forced labour, according to anti-trafficking charity Unseen UK, generating £120 billion ($150 billion) in illegal profits every year. Of these, 11.4 million are women and girls.

In the UK in 2015, 3,266 people were identified as potential victims of trafficking, an increase of 40% on the previous year.

US Senator Bob Corker, who introduced the End Modern Slavery Initiative Act in the States, says that the real figure is even higher. “There are 27 million slaves today in the world, more than at any time in the world’s history,” he told CNN earlier this month.

The Republican politician continued: “In every country in the world it’s illegal, but it still exists, including here in [the US], and we should end it. And I think we’ve begun the effort of bringing the world community together around this.”

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Last week, Kutcher – the co-founder of anti-child abuse charity Thorn – made headlines when he delivered a moving speech about his anti-trafficking work to politicians in Washington D.C.

“As part of my anti-trafficking work, I’ve met victims in Russia,” the actor told a Senate committee. “I’ve met victims in India. I’ve met victims that have been trafficked from Mexico. I’ve met victims in New York and New Jersey and all across our country. I’ve been on FBI raids where I’ve seen things that no person should ever see.

“I’ve seen video content of a child that’s the same age as mine being raped by an American man that was a sex tourist in Cambodia,” he continued. “And this child was so conditioned by her environment that she thought she was engaging in play.”

To take part in the End It awareness campaign, you can find downloadable resources at their website – including red X’s to be uploaded to your Facebook, Instagram and Twitter profiles.

The campaign is also asking supporters to draw an X on their hand in red lipstick and take a photo to post on social media, using the hashtag #EndItMovement.

You can also sign up to be a digital defender against child sexual exploitation, volunteer with UK anti-trafficking groups, and donate to the End It Movement.

Images: Rex Features, iStock