I did not add sources to the post, since they are all in Norwegian. I believe I should be able to dig up sources for all fact claims in the article above. Just found this article from 2017 with a list of municipalities and percentage of children "taken" by Barnevernet. The average all over the country is 0.8%, but the worst municipalities have like 3-6%. That's a lot! (of course, the numbers are colored by the fact that Norway have a lot of very small municipalities, so for sure there are some outliers by pure chance. The list does not include municipalities with 3 or less displaced children though).

https://www.nrk.no/nordland/der-barna-blir-henta-av-barnevernet-1.13771315