Dotcom was arrested by New Zealand Police, cooperating with FBI. Copyright is governed by international agreements, one of which is Berne Convention, first signed in 1886. New Zealand and US are Berne Convention signatories.
To be essentially the same, first US would sign Data Protection Directive, then Germany would request FBI to cooperate, and FBI would raid Facebook HQ.
That's not what happened. Kim Dotcom was arrested by NZ police.
Just about all extradition treaties require "double criminality", where the person is extradited on a thing that's a crime in both countries. The USA does not have these data protection laws, so the USA is highly unlike to extradite to a country where that's illegal.
I am not sure. I agree that while copyright is governed by international agreements, this case probably falls outside of what is agreed. I don't think safe harbor provisions are harmonized across jurisdictions.
The answer is because they respect the rule of law, a better analogy would be why can't germany use drone strikes or extraordinary rendition against Zuckerberg.
We can't do any drone-strikes because we do not have drones (that are equipped with firearms). We just bough some from the US but I do not think that they have arrived already. Would be interesting to know how many parts in these drones are actually made in Germany.