Passport confiscation is a common sign of modern slavery.

    "he was lured in with the false promise of a well-paid job in the UK"
    "The gang confiscated the passports of all their victims"

It's not legal. There are definitions of "Modern Slavery" and descriptions of the practices and warning signs because it is still an issue in contemporary times, including in Europe.

https://www.bbc.co.uk/news/articles/c2kdg84zj4wo

No, it's real. Every year, there are several news articles about berry pickers being abused, at least here in Sweden (not sure about the other Scandinavian countries). Here's [0] just ONE of the myriad of articles I could find, but there are so, so, so many more (and even worse ones) [1].

[0]: (In Swedish) Berry entrepreneurs suspected of trafficking Thai nationals, (2025). https://www.svt.se/nyheter/lokalt/vasternorrland/barforetag-...

[1]: (In Swedish) Berry pickers (Topic). https://www.svt.se/nyheter/om/barplockare

Both are from SVT, the public broadcaster in Sweden.