Depends on the terms!
I work four jobs, all freelance, all paid sufficiently and all zero hour.
Suits me really well, as the work comes and goes between the different roles I’ve always got something to do.
It’s the exploitation of them that’s the problem. It’s the way they’re used to make people disposable and bypass employment laws that’s the problem.
Countries have treaties around mutually enforcing intellectual property, probably would come into play here and allow for the US party to file a claim against them in a European court.