The European Court of Justice is to decide whether Germans born outside Germany and given hyphenated last names there can keep them. FAZ some months ago:
bq. Das Rechtsgutachten beschäftigt sich mit dem Fall des Kindes Leonard Mathias Grunkin-Paul. Der Junge wurde 1998 in Dänemark geboren und lebt auch überwiegend dort bei seiner Mutter in der Ortschaft Tønder. Seine deutschen Eltern haben verschiedene Nachnamen, aber selbst keinen Doppelnamen. Die dänischen Behörden trugen deshalb nach dortigem Recht einen Doppelnamen in die Geburtsurkunde ein.
The Independent reports:
bq. German bureaucrats fear a hyphen pandemic. A child with a double-barrelled name, they point out, could go on to marry someone with a double-barrelled name. Their children would have four linked-up surnames, and the next generation might have eight.
Apparently there has been an opinion by Advocate General Jacobs, but I haven’t succeeded in finding it. It sounds as if the Germans will have to give way. But I think anything that can be done to stop Germans having eight-element hyphenated names can’t be all bad.