Years ago I watched a video of a young woman foreign worker from I think Philippines kill herself because of abuse. It really haunted me. And more research showed it's pretty common, as well as unsafe labor to the point of death, mostly all in middle eastern countries.

So, since then, my answer is modern day slavery. Wherever and however it exists.

Don't need unlimited resources to start, just to make a living.

Would likely need unlimited resources both monetarily and legal to actually attempt to tackle it, though.

If I had any real idea of how to start, I'd have done so yesterday.