A lot of the times, when children get taken away, it's for good reasons, like drug abuse, crime, violence or sexual abuse.
But Norway is in the middle of a giant moral panic about teen crime. The justice system recently implemented a new system to hasten the punishment of teenagers and lowered the age required to be sent to prison.
All of these measures are heavily biased towards teens of immigrant families. Middle Eastern looking kids hanging out in a shopping mall will frequently get the cops called on them for loitering around, and that results in CPS involvement, meaning families that are visibly foreign are much more subject to scrutiny for simply having a normally rowdy teenager.
Our CPS equivalent are also infamous for using sloppy "interrogation" tactics and often twist the words of children and lead them on to get a conviction against their families. Especially so against immigrants.
Don't get me wrong, I'm not against CPS-like services. I just realise that it is a double edged sword. Open for exploitation for those with horrible intentions, and a crucial service for people who really need it.