(Private) Prisons. Prisoners have no labor rights in the US and earn cents per hour making textiles, office furniture, military wire, id-tags, vests, etc. Private prison corporations contract out this labor to clients like the DoD, Wal-Mart, Costco, etc.
It creates an incentive for the prison industry to lobby for more prisons, tougher anti-crime laws, tougher border crossing penalties, longer sentences. The profits incentivize a total lack of addressing recidivism.
1 out of 4 prisoners in the world occupy a US prison (we account for what? 4-5% of the world's population?). Violent crimes have been trending down over 20 years, but prisoner population as a percentage is at an all time high due to tougher drug convictions.
Also, then there's huge factory farms, which are known to use migrants of questionable citizenship as laborers, and report them to the police when they complain.
I certainly wouldn't call illegal immigrants slaves. They generally speaking work under stolen identities and pay taxes for non-cash payment just like the rest of us. For those that do work strictly for cash, yes what you said does happen, but they are breaking the law to begin with by being illegal immigrants. The current US administration has made it a lot easier for said illegals to get less scetchy jobs via the DREAM act and the associated legal things.
The points you bring up about prisoners is interesting. I've always found the moral idea of a for-profit prison as reprehensible.
Every few years since, IIRC, at least the mid- to late-1980s there seems to be a new exposé about various forms of slavery in the Commonwealth of the Northern Mariana Islands (particularly Saipan), though that may have been at least somewhat mitigated in the last few years by Congress' federalization of CNMI labor and immigration policy in 2008.
The term mostly used nowadays to describe the selling of people is "human-trafficking" even though human trafficking is a little bit broader category. Its common for organized crime to deal in human trafficking.
