For Filipina teenager Ruby, a Facebook message offering a job in a cyber cafe across the country seemed too good to be true.
Days later, the 16-year-old orphan was dragged in front of a webcam by her new employers and forced to perform sex acts for clients - becoming another captive in the growing global slave trade to be lured, trapped and abused through technology.
"It was like a bomb exploded ... I had been totally fooled," Ruby, now 21, told the Thomson Reuters Foundation at the back of an empty church in Tagaytay city in the Philippines.
"I felt degraded and disgusted - I blamed myself," she said. "I was forced to do things you could not imagine a 16-year-old having to endure."
Modern technology - be it mundane messaging apps or complex cryptocurrencies - is fuelling the modern-day slave trade by enabling traffickers to ensnare more victims, expand their illicit empires, and outfox law enforcement, experts say.
With a click, tap or a swipe - it's all at their fingertips.
Now experts wonder if the same high-tech toolkit can be used against the traffickers to rescue victims and stop slavery.
"Traffickers can obscure what they do, alter their tactics and change their codes," said Wade Shen, programme manager at the U.S. Department of Defense's research agency (DARPA).
"But we are good at keeping up with them despite these tricks," he added. "This is a cat-and-mouse kind-of-game."
Enticing people with jobs on Facebook, selling victims for sex on marketplace websites, tracking slaves via webcam and their phones: tech underpins an industry estimated to control 40 million people and generate annual profits of $150 billion.
From factories and fisheries to nail bars and migrant camps, more people are believed to be in slavery now than ever before.
The average modern slave is bought for just $90 - against a price tag of $40,000 about 200 years ago - researchers say.
"Technology has lowered the bar of entry to the criminal world, which has had an expansive effect on modern slavery," said Rob Wainwright, a British ex-diplomat, who ran Europe's policing agency Europol for nine years until this year.
Rising internet use - 4 billion people were online last year up from 2.5 billion in 2012 - means many more potential victims, as well as a widening worldwide pool of customers to be tapped.
The global spread of cheap, fast internet and surging smartphone ownership has taken slavery into a new age.
This high-tech leap leaves police and prosecutors chasing shadows in a virtual world as they strive to meet a United Nations goal to end forced labour and modern slavery by 2030.
"Technology is taking slavery into a darker corner of the world where law enforcement techniques and capabilities are not as strong as they are offline," added Wainwright, now a senior partner at accountancy firm Deloitte's cyber security practice.
With modern slavery now regarded as a major global threat, experts are asking if digital tools - from blockchain to satellites - can help turn the tide as law enforcement, civil society, banks, businesses, and techies take on the traffickers.
The world's top police agencies, Europol and Interpol, are ramping up operations as slavery emerges in cities everywhere.
The former - which polices Europe - saw a 14 percent increase in cross-border slavery and trafficking cases in 2017, with more than 50 top priority operations against the crimes.
Interpol has rescued about 850 suspected victims of slavery and arrested at least 60 potential traffickers in major crackdowns in West Africa and Central America in the last year.
However, human traffickers are often at least one step ahead of police, who often lack computing expertise and experience, are unfamiliar with modern tech, and are hindered by limited international cooperation to crack cases, according to insiders.
"We have this online Wild West where people are exploiting others with impunity in plain sight," said Nazir Afzal, a lawyer and former British chief prosecutor, who fought some of the biggest cases involving sex slavery and child abuse in Britain.
Yet technology may be a double-edged sword for slavemasters as law enforcement agencies get up to speed on the latest tools.
For human traffickers leave behind digital fingerprints that can be traced, while modern tech - from satellites and eye-scanners to blockchain and artificial intelligence (AI) - could boost global efforts to eradicate forced labour and sex slavery.
Blockchain's digital ledger technology is being trialled to protect children in Moldova, and workers in Coca-Cola's sugar supply chains, while Thailand has turned to satellites to tackle forced labour among fishermen in its lucrative seafood industry.
But it's not all high-tech in the fight against traffickers.
Video conferencing is enabling trafficking victims to give evidence remotely in cross-border cases in India, Bangladesh and Nepal, while employment websites in southeast Asia are helping maids seeking work abroad avoid enslavement by abusive bosses.
Abused, hit and treated like an animal by her first employer in Hong Kong, discovering one such site afforded Filipino maid Genelie Millan options for the first time in her working life.
"When I first arrived (at the new employer), I felt at home straightaway - the kids kept hugging me and were very excited," said the 39-year-old, who left the Philippines in 2010 for work.But it's not all high-tech in the fight against traffickers.
"They treat me like their family, they trust me a lot."
Modern technology has the potential to break the dominance of traffickers and slavemasters over their victims, said Luis deBaca, a U.S. lawyer and former ambassador who led the government's anti-trafficking efforts under President Obama.
"Early-stage technologies really helped traffickers to thrive in their business," deBaca said. "Now, it's our turn."
Technology has helped modern slave drivers reach out farther and faster to advance their lucrative trade in human beings.
Social media aids recruitment, stolen credit cards finance travel, victims can be monitored virtually and sold online before proceeds are laundered - electronically, of course.
Fresh victims can be recruited, transported worldwide and trapped in slavery in just days - compared to months in the past - with police often barely able to react, criminal analysts say.
About 600 trafficking routes globally have been identified - in every region of the world - an increase of almost a quarter between 2007 and 2014, according to the latest U.N. statistics.
Instead of lurking in malls, train stations, homeless shelters and brothels to find vulnerable people, traffickers have a plethora of digital tools to target potential victims.
"Take Moldova, for example, in the past you could visit any village or town, identify the middlemen and find out what was happening," said Radu Cucos, an official at the Organization for Security and Cooperation in Europe (OSCE), a security watchdog.
"Now, you cannot do that ... everything is hidden online."
Every day, hundreds of billions of messages are sent, posts written and calls made over apps and websites such as Facebook, Whatsapp, and Skype - the perfect hiding place for traffickers.
"Facebook is really a primary social media medium for traffickers to engage susceptible and vulnerable victims into the trade," said Kevin Campbell, vice president of global operations at U.S.-based anti-trafficking group The Exodus Road.
Traffickers tend to advertise victims over listings and sexual services websites rather than the dark web - part of the internet beyond the reach of search engines - as this offers them a far bigger pool of potential buyers, according to police.
The vast reams of content online, and the encrypted nature of modern tech - police in many nations can intercept phone but not WhatsApp calls - provides cover and a cloak for traffickers.
"Traffickers can hide among the sheer volume online," said Dan Parkinson, an officer at Britain's anti-slavery police unit.
Tech is also helping criminals to evade detection in the offline world as they can plot and perform abuse from home - such as cybersex child trafficking where sexual exploitation is broadcast around the world to paying customers, charities say.
In the Philippines - a major source nation - local abusers and global clients from Australia to Canada are outsmarting police by mixing up payment methods, using cryptocurrencies, and streaming over encrypted livestreams that are tough to trace.
"Exploitation begins online ... but often leads into offline physical sex exploitation, (and) trafficking," said Lotta Sylwander, country head for the U.N. children's agency (UNICEF) based in the Philippines. "And the victims are getting younger."
Facebook - which owns WhatsApp - said its security experts pull content relating to trafficking, and work with law enforcement, civil society and the U.N. Office on Drugs and Crime (UNODC) to share findings and report crime.
Microsoft - the parent of Skype - said it funds research to learn how criminals misuse tech, develops software to spot child sex exploitation, and collaborates with other tech firms and police to refer crimes for follow-up and prosecutions.
"While these efforts are not a perfect solution, we continuously invest in new ways to address the problem ... child sexual exploitation is a horrific crime," a spokesman said.
Teams from tech giants including Facebook, Twitter, Google, Microsoft, and Uber united last month for an annual hackathon to develop and test tools to combat online child sex trafficking.
Police and cyber security analysts say cooperation from web companies in tackling human trafficking is inconsistent - but that new U.S. legislation could change the landscape.
The law penalises website operators that facilitate online sex trafficking, and makes it easier for prosecutors and victims to sue sites that keep exploitative material on their platforms - if they can be shown to have knowingly done so.
Yet this could simply spur traffickers to advertise their victims on sites run by overseas companies in countries which are out of the reach of U.S. authorities, legal experts say.
"That is really scary," said Maureen Guirguis Kenny, co-director of the Human Trafficking Law Clinic at Case Western Reserve University in Ohio. "That's the dark side of this."
Internet giants aside, law enforcement agencies are also teaming up with banks, charities, and tech and data analysts to utilise diverse networks to identify and track the traffickers.
Financial institutions in the United States and Europe - which are required to report suspected illegal activity - are working together to share data and develop software to spot and disrupt human trafficking, and help police prosecute the crime.
"Traffickers use various accounts across several nations and transfer small amounts to move money through banks undetected," said James Heinzman, an executive vice president at Israeli-based cybersecurity and big data analytics company ThetaRay.
"We are seeing unprecedented sophistication from traffickers in terms of laundering money," the financial crime expert added.
A fearful customer, a flurry of late-night transactions or suspicious documents; banks look out for patterns among regular purchases, from cosmetics and rent to food and fuel, as traffickers often use victims' accounts to run their businesses.
"So you don't see normal activity for a woman - buying normal things like buying groceries and cosmetics ... but advertising online, fast-food, travel, hotels, frequent taxis," said Peter Warrack, formerly of Canadian-based Bank of Montreal.
"It's not what you see, as much as what you don't see," added the former director of anti-money laundering at the bank.
Banks are using machine learning algorithms to look beyond transactions and examine how suspects access their accounts, the digital footprint of their device, and other less obvious signs.
But the odds of finding red flags are slim.
Less than 1 percent of the estimated $1.5 trillion plus laundered by criminals worldwide each year through the financial system is frozen or confiscated, according to UNODC statistics.
"This is not a case of looking for a needle in a haystack - it's more like a needle in a stack of needles," Heinzman added.
Data analysts are also testing software they hope will sift online sex adverts to find those posted by human traffickers.
The same contact number, username and blurb on multiple ads are possible signs, while descriptions such as 'new', 'young' and 'fresh' may mean a woman is underage or a slave.
Algorithms decode language, make links between seemingly unrelated posts and tie data underpinning bitcoin payments - the primary currency for buying sex online - to the adverts.
"Money doesn't lie," said Rebecca Portnoff, a research and data scientist at U.S.-based tech anti-trafficking group Thorn, which was co-founded by actors Demi Moore and Ashton Kutcher.
"(An algorithm) can reduce the set of possible bitcoin transactions that paid for an online sex ad from millions to half a dozen, or even just one," added Portnoff, who based her findings on the recently-seized sex marketplace site Backpage.
In April, U.S. law enforcement agencies shut Backpage.com, a classified advertising site that some analysts believe accounted for 80 percent of online sex trafficking in the United States.
While the closure was hailed as a breakthrough, digital analysts say it may just drive slavemasters to other websites.
There are also fears that as the high-tech net closes in on traffickers, they will simply up their game and grow smarter.
"We want to innovate as quickly as the traffickers - with deep learning, algorithms and facial recognition to predict and foresee their tactics," said Emily Kennedy, chief executive of Marinus Analytics, a U.S.-based anti-trafficking tech startup.
"But we don't want to spur change and innovation in their criminal practices ... it is a fine line that we have to walk."
Hacker collectives are also playing a role by helping police to gather digital evidence, or acting alone to trawl through data including sex ads, visa blacklists, and other databases.
These virtual vigilantes aim to stop traffickers before they exploit people, yet legal experts say they may obstruct justice if their self-gathered evidence proves inadmissible in court.
"We're not here to save the world," said Sergio Caltagirone, of the Global Emancipation Network (GEN), a tech anti-trafficking collective, which said one investigation resulted in the group identifying about 1,000 traffickers online last year.
"But we are here to make people who are saving the world even better at doing it," the GEN's technical director added.
Businesses are also using tech amid rising regulatory and consumer pressure to ensure their supply chains are slave-free.
From cosmetics and clothes to shrimp and smartphones, supply chains are complex, often with multiple layers spanning several countries, making it tough to pinpoint and tackle exploitation.
But blockchain, the system tracking cryptocurrencies such as bitcoin, could prove a new frontier in the anti-slavery drive.
"Leading companies are beginning to recognise that blockchain provides a way to increase trust in their products," said Dan Viederman, a managing director at U.S.-based foundation Humanity United, set up by Ebay founder Pierre Omidyar in 2005.
It is being tested to trace cobalt's journey from Democratic Republic of Congo to ensure metal in lithium-ion batteries for products from iPhones to Teslas has not been mined by children.
Coca-Cola and the U.S. State Department are teaming up - in the government's first major project on forced labour using blockchain - to protect workers in global sugar supply chains.
But abuse will only end if technology is backed with bold action by businesses, according to Danielle McMullan of Britain's Business and Human Rights Resource Centre (BHRRC).
"Resolving workplace grievances or rights violations cannot lie with technology," said Cindy Berman, head of modern slavery strategy at the Ethical Trading Initiative, a network of trade unions, companies and charities. "It is not a silver bullet."
Beyond businesses, blockchain is being piloted by the United Nations in a world-first scheme in Moldova to give children a digital identity, based on eye scans and fingerprints, to guard against human traffickers who exploit lax border controls.
The scheme has critics, who say children are mainly exploited in Moldova or trafficked out with valid documents.
Yet the government says it has no choice but to innovate.
"Many times authorities are late in using latest technologies and innovations," said Mihail Beregoi, state secretary for the Moldovan Ministry of Internal Affairs.
"We need to be alive and think about the future ... any effort to secure at least one child is already worth trying."
For Laura, a 36-year-old mother-of-one from Moldova who has twice been trafficked to work and sell sex in Russia, blockchain could save girls like her young daughter from a similar fate.
"I had a lot of suffering," she said at a rehabilitation centre for victims of violence in a village in northern Moldova. "I am very afraid of being sold again, afraid about my child."
But it's not just bitcoin and blockchain on the front line. Everyday tools - be it Skype or job sites - can set slaves free.
From car wash to construction site, nail bar to refugee camp, slaves are hidden in plain sight the world over.
Different search and rescue tools fit different jobs.
In Thailand, satellites, optical scanning and e-payment services have been rolled out to prevent forced labour in its multibillion-dollar seafood industry, where many migrants work.
The raft of digital measures is intended to help labour inspectors identify victims, pinpoint slave vessels and ensure workers do not have their wages withheld. Yet such technology is impotent in isolation, said U.N. trafficking expert Ben Smith.
"You need good information, intelligence ... (to know) where to look," said Smith, a UNODC project coordinator in Southeast Asia. "(Tech) has to be a small part of a much bigger effort."
At the other end of the spectrum, job matchmaking websites cut out middlemen and help domestic staff avoid abusive bosses in countries such as Hong Kong - often a trouble spot for maids.
"Recruitment is so mired in these unethical things is because there are too many players and no accountability," said Victoria Ahn of the Fair Employment Agency (FEA), which offers a platform for employers and domestic helpers to connect directly.
"Technology will play a huge role in clearing that up and reducing the number of players," said Ahn of the FEA, which has made 2,000 connections since 2015 and saved workers about $3 million - money that would otherwise have gone to recruiters.
Elsewhere in Asia, video calls could revolutionise the pursuit of justice in trafficking cases spanning India, Bangladesh and Nepal, allowing survivors to go home after being freed or rescued and to testify via software such as Skype.
Human trafficking convictions in India are rare as most victims drop cases if forced to testify in court, face their abusers, and stay in a shelter throughout often lengthy trials.
"When I was questioned by Indian authorities after I was rescued from near Mumbai, I lied because I was scared," said Neha Maldar, who was trafficked from Bangladesh to sell sex.
"But during the trial, I was in my own country and there was no fear," Maldar added. "I saw the people who had trafficked me on the screen and I wasn't scared to identify them."
"I was determined to see them behind bars."
Modern slavery is increasingly dominating global headlines - from a landmark collective estimate on the number of slaves worldwide, to countries from Australia to India looking to follow Britain's lead by adopting tough anti-slavery laws.
About 40 million people are living as slaves - in forced labour and forced marriages - and seven in 10 victims are female, according to research by the U.N. International Labour Organization (ILO) and human rights group Walk Free Foundation.
But despite growing international collaboration on anti-slavery laws, data and funding, law enforcement cooperation is often lacking, said UNODC's Kristiina Kangaspunta.
"I've worked on human trafficking for 18 years and seen very few, if any, good practices on international cooperation," said the chief of its crime research section, explaining how requests from poorer nations to major countries often get overlooked.
"Countries lack the capacity and training to tackle crimes online ... so they aren't capturing newer forms of trafficking."
With more people falling into slavery each day - pushed by war and disaster, greed and inequality - experts fear technology has given human traffickers the edge over those giving chase.
"It's like a game of cat and mouse," said Afzal, the former chief prosecutor. "But the cat has two legs tied together."
|Reporters||Anastasia Moloney, Anuradha Nagaraj, Beh Lih Yi, Heba Kanso, Inna Lazareva, Rina Chandran, Sebastien Malo, Umberto Bacchi|
|Text editing||Belinda Goldsmith, Katy Migiro, Lyndsay Griffiths|
|Multimedia editing||Georgina Cooper|