CNN- well, CNN International, anyway; CNN US is too focused on politics- has a really nice ongoing thing called the Freedom Project. The Freedom Project is an effort to expose modern-day slavery, wherever on the planet they happen to find it. As they reported about a week ago, the International Labour Organization estimates that 20.9 million people worldwide are living in slavery, 4.5 million of which are sex slaves. That's just an estimate, though; this isn't the antebellum South. Nobody is going around these days bragging about how many slaves they have, save for possibly pimps. (Yes, that counts.) It could be up towards 30 million.
In any case, slavemasters aren't exactly forthcoming. Neither are many of the slaves themselves, who are often in a position where coming forward means they would be arrested and prosecuted themselves for whatever it is their master made them do. So what tends to happen is every time slaves get unearthed in the Western world, it comes as a surprise to people- 'wait, we still have slaves here? The Civil War ended, right?'
If slavery is found in Mauritania or China or Afghanistan, on some level that falls in line with people's expectations. A general lack of freedoms means people might expect to see slavery result. But they don't expect to see slaves in, oh, say, Sweden.
Hope you're sitting down, because the ILO thinks it may have found slavery in Sweden, in the form of berry pickers. Specifically, workers brought in from eastern Europe and Asia, from whom their employers suddenly withhold payment and disappear.
I'll let the article, at ScienceBlog, go into detail on it.