People in forced labour jobs turn up in the most surprising places - a lap-dancer in London, a fairground worker in Germany, a farm-worker in Ghana, or a child in a textile factory in India - all could have been forced in some way to do the job they do.
In bringing out its second major investigation into the problem in this century, the International Labour Organization (ILO) is hoping to see if there are any trends which can be deduced, and most importantly, if there are any solutions which can be found.
War provides a growth area for modern slavery
Although the target date of 2015 for eradicating the world of one of its ancient abuses is already looking unrealistic, there are some signs of change in a positive direction.
In the increasingly flexible world job market, not all economic migrants are victims of forced labour.
And the report is careful to draw a distinction between people who have gone overseas to work with the ability to return, and those who find themselves trapped, with their documents removed, threatened with being turned in to the authorities if they disobey orders.
FORCED LABOUR FACTS
12.3m victims of forced labour worldwide
2.4m in forced labour because of trafficking
$31.6bn annual profits generated by forced labourers
The report finds a significant amount of the kinds of forced labour which have been known about for a long time: bonded labour, where children grow up bound to do the same jobs as their parents with no real chance of release, people abducted into slavery in West Africa and Sudan.
War provides another growth area for modern slavery, with the seizure of children as soldiers or sex-slaves in war zones.
The continuing threat to hundreds of thousands of children in the war in northern Uganda remains the worst child-abuse scandal in the world.
But it is in the newly globalised economy that the report sees the biggest deterioration, as people-trafficking has grown into a $30bn dollar global industry.
About one in six of the total number categorised as victims of forced labour, or 2.4 million people, are victims of the people traffickers.
Often they may have handed over their life-savings for the promise of a better life, only to find themselves unable to return home, or they may go to visit family, and be drawn in to tight-knit communities - this is particularly true in the textile industry, which is notoriously difficult to regulate.
It often takes a tragedy to force through new legislation
The sex industry, agriculture and construction, and domestic service across the world all come out in survey after survey of forced labourers as being the worst offenders.
And it often takes a tragedy to make a difference.
The deaths of more than 20 Chinese cockle-pickers who were drowned off the north-west coast of England last year led to a new law in Britain regulating the "gangmasters" who were managing their affairs.
But this law is an exception.
While welcoming the change, the ILO report concludes that laws are often not specific enough.
While countries may sign up to international conventions and have a stated opposition to forced labour in general, actual prosecutions are very rare, since laws are not carefully directed to catch offenders in the informal, under-regulated world of the private-sector cash economy where three-quarters of this modern slavery goes on.
However, worldwide awareness that there is a problem is growing.
The sex industry is one of the worst offenders
Increased UN concern about organised crime, given a new sense of urgency after 9/11, has now led to a new international protocol against people trafficking.
And, when Europe issued a declaration in 2002, designed to combat people trafficking in the sex industry, it linked the problem specifically with other forced labour issues worldwide.
It is all part of a growing trend called "fair globalisation".
There have been new laws in Asia where the bulk of the victims of forced labour live.
In Africa, even in countries badly damaged by conflict, there are positive signs too.
It will take a lot to change the culture of forced labour, since it operates best in informal areas outside the view of the normal economy
Trade unionists from a disparate group of countries, from Burundi to the Democratic Republic of Congo met in Cameroon late last year to discuss a wide range of issues, including slavery and abduction, debt bondage, forced domestic labour, the sex trade, and people-trafficking.
It is in these smaller-scale, non-governmental meetings that the problem could find its solution.
In Tamil Nadu, in southern India, village "vigilance committees" are being set up to stamp out bonded labour.
Local individuals, with a business knowledge, are far more likely to uncover the practice than formal investigators.
But, realising the considerable competitive advantage that cheap labour gives it, India has been slow to agree to international demands to eradicate its dark side.
It will take a lot to change the culture of forced labour, since it operates best in informal areas outside the view of the normal economy.
And that's why the ILO's decision to focus more of its time and attention on to it has to be welcomed.