Millions of men, women and children around the world are currently victims of human trafficking - bought and sold as commodities into prostitution and forced labour.
This trade in people criss-crosses the globe - and it is a lucrative business. The International Labour Office estimates that forced labour generates $150bn (£96bn) in illegal profits every year. Two thirds ($99bn; £63bn) comes from sexual exploitation.But who are the people behind the numbers?Thousands of women and girls from West Africa are bought and sold every year - most end up in Europe. The UN's Office on Drugs and Crime estimates West African trafficking victims, many of whom originate in Nigeria, make up about 10% of those forced into sex work in Western Europe.
Benin City, in Nigeria's south, is a key player - with networks and infrastructure built around the trade in people.There, traffickers scout for girls wanting to travel, enticing them with promises of work and education. The victims are offered false papers and told they will need to pay off the cost of their transit when they reach their destination country.
Once recruited, the girls are often forced to take part in rituals to ensure their compliance.
One female former trafficker in Benin City describes how traffickers take girls' clothes as well as hair from their head, armpit and pubic area and hand them over to a traditional preacher in a ceremony, as a pledge that they will pay back their debts.
"With all those things collected from them, they have this fear that anything can happen," she says.On her arrival in Italy, Kemi, a Catholic, soon learnt that the reality of her new life was far from what was promised.
She was told she would be expected to work as a prostitute. Although she initially refused, after being denied food and having her phone taken from her as punishment, she began to do as she was told.
"In the end, I worked for three years and three months," she says.
Over that time, Kemi paid a total of €27,000 ($30,000; £19,000) to her traffickers - an amount they were still not satisfied with.
She eventually found the strength to leave their clutches and escaped to stay with friends. However, she was deported by Italian authorities back to Nigeria some time later.
Apple threatened to remove Facebook's apps from the App Store in 2019, following a BBC report that showed human traffickers set up 'slave markets' to sell women to the highest bidder, according to The wall street Journal .
The WSJ obtained internal documents from the social media firm that detail how its own employees were searching for human traffickers in the Middle East.
Facebook investigators found these groups posted advertisements for domestic workers as a front for selling women off as slaves or sex workers.
The WSJ found that Facebook does remove some of these pages, but it has yet to design a system that stops offenders from reposting under a new account.
A Facebook spokesperson told DailyMail.com in an email that they social media firm has 'had people working on this issue for many years but expanded our efforts to include a dedicated team in 2019.'
'We do not allow content or behavior on Facebook or Instagram that may lead to human exploitation, the continued.
'Our policies are developed in consultation with expert organizations, including the UN, and do not allow people to post content or accounts related to domestic servitude.
'We've been working to combat human trafficking for domestic servitude on our platform for many years.'
On the other hand, fixing this system does not put money in Facebook's pocket and the company would rather spend its time retaining users, helping business partners and 'at times placating authoritarian governments,' according to WSJ.
Brian Boland, a former Facebook vice president who oversaw partnerships with internet providers in Africa and Asia before resigning at the end of last year, told the paper that the social media company looks at abuse in developing countries as 'simply the cost of doing business.'
The WSJ notes that Facebook's investigation team spent more than year documenting a booming slave trade in the Middle East, all of which was happening on its own apps – specifically the main Facebook app and Instagram.
They found offenders shared photos, skill description and personal details of their victims, along with a specific hashtag that buyers know means they are looking at sex workers.
Facebook was found to have removed some of the pages, but this only occurred after Apple threatened to remove it from its App Store, according to the WSJ report.
And the threat was in response to a BBC story on maids for sale.An internal memo found that Facebook was aware of the practice even before then: A Facebook researcher wrote in a report dated 2019, 'was this issue known to Facebook before BBC inquiry and Apple escalation?,' per the Journal.
And the answer includes: 'Yes. Throughout 2018 and H1 2019 we conducted the global Understanding Exercise in order to fully understand how domestic servitude manifests no our platform across its entire life cycle: recruitment, facilitation, and exploitation.'
The internal documents also note that Facebook is limited in how it operates in some countries due to the language barrier.
The social media firm, according to the documents, has few to no people who speak specific dialects necessary to identify such criminal acts.