Looking at Sweden and the issue of human trafficking in construction, cleaning and farming, the general problem is that the fine businesses are employing independent contractors from multiple layers of hiring firms, and no one seems very interesting to hold the people who is benefiting from the labor responsible.

It is a well know open secret that not only do practically every large construction site employ illegal immigrants, but there is also a tier system for who do what job. The highest risk and longest hours are given to illegal immigrants. The next tier are those that work off the books, and then last we got those that operate legit as there need to be at least a few of those. This setup seemingly works, until there is an accident or the hiring firm suddenly refuse paying the illegal workers and the miserable details of the human slavery becomes news for a day.