system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does Human Trafficking work in America?

I hear about human trafficking being a huge problem in the modern world but I don't understand how it works, especially in the developed parts. So here are a few questions about trafficking...

1. Is human trafficking slavery, and if not, what exactly is it? 
2. What purposes do trafficked humans serve?
3. What would a scenario of a human being trafficked in America look like? Prostitute? Garment workers? Etc.? 
4. How can actual human beings be trafficked in developed nations where surveillance and documentation seem like they would make the act very difficult to hide? 
5. And lastly, who exactly is doing the trafficking? Gangs? 

thanks, and sorry if my questions sound ignorant, but I very much so am in this area, which is why I am here!
gpt
1) Is it slavery? It depends on the specific circumstances, but usually yes it is exactly that. A person is forced by somebody into a position to do a task with no way out - that's pretty much slavery. Some will argue that technically its not and argue over semantics, but for all intents and purposes it is slavery. 

2) What purpose do they serve? Generally speaking it is either prostitution or to provide labour for menial jobs for next to no money.

3) Scenario? The end work (prostitute, menial labour) makes no real difference - the story is usually the same. Criminals target individuals in poor countries, these are people who have nothing. They are told that for just $x they can start a new life in the West - the criminal will tell them that for this money they have a job lined up, somewhere to live sorted, food arranged, all transport, travel documentation,  etc. The criminal makes it seem like such a good deal that they somehow get the money together, often entire families will work and save for 2-3 years to get enough cash together to send their child away to this better life. The criminal gets paid and buys a plane ticket and the person comes to the new country full of hope. They then arrive where they are thrown into the harsh reality. They will be put into a small apartment with 10 others living in the space suitable for only 1 or 2 people. They will then be told that they have to work to pay-off their debt. The criminal will tell them that they now owe a huge amount of money, the kind of money that they can never realisticly earn doing their job....  and their job will be horrible menial labour or prostituion. They will have to work every hour of every day, for next to no money, living in these horrible places. And there is no way to escape. The criminal gangs will keep them locked in, they have no contact with the outside world, they cannot call for help.... they just vanish. Hopefully some day the police will find out or someone will escape and raise an alarm, but this can take years and may not even happen. Its tragic. Also, in some cases, the criminals are now skipping the entire first step of convincing people its a good idea to pay money to have a new life, and are simply kidnapping people and smuggling them in on boats like cattle. Unimaginable but it happens sadly.

4) How can it happen with surveillance etc? See answer 3 - they are locked up, no one knows they exist, they are under lock and key 24/7, their criminal keepers basically hold them hostage. Unless they can somehow escape, there is no way to raise an alarm. Law enforcement have large efforts to try to find and stop these rings, but its a drop in the ocean sadly.

5) Who is doing it? See answer 3 - its large international criminal organisations. As for who is buying the service, its the men seeing the prostitutes and its the unscrupulous employers who will pay the criminals for the cheap labour.