Germany's actions become more contorted in their reaction to the revelations of spying. It appears that the British embassy has undertaken surveillance of Berlin. No doubt this has been taking place since the beginning of the Cold War with various permutations. As the Telegraph article notes, the Russian embassy is only one street away (and I wonder where the French embassy is).
The German Foreign Ministry has called in British embassy staff in Berlin for an explanation. If they do extend this path of displeasure and create further difficulties with the 'Five Eyes', this will represent a further turn towards neutrality in Mitteleuropa; a turn noted in Atlanticist capitals and a further reminder that NATO remains in form, but that trust in collective action must further diminish.