I don't think the refugees themselves are the problem. Most of them seem to be grateful and nice.
The real problem will be their offspring. They either become thugs, rapists and criminals like these algerians and turks or they form new terror cells within europe to revoke the former ISIS caliphate from thier homelands (syria and iraq) in future.
So we need to get rid off them before they start attending kindergarten and elementary schools.
Take care of the refugee problem and you take care of the offspring problem. They're failed parents that's why the kids become criminals, rapists and jihadis.