In the US I saw engineering labs using PhDs from abroad as almost slave labor. A bit hyperbolic perhaps, but the students were not allowed to progress without the advisor's say so, and the advisors would not allow them to top-author papers they were basically sole contributing. On top of that, between their own work and lab work, they were expected to put in 60 to 80 hours a week.
The point is, the power dynamics were out of whack.
The point is, the power dynamics were out of whack.