Will the investigation get anywhere; who should be prosecuted?  The biggest problem facing an investigation by a prosecutor is whether there is any point in the investigation. Who could be relevant witnesses? Would any of them cooperate? [1] Ultimately who do you prosecute? Germany might be able to bring some of the US staff in Germany who conducted the surveillance to trial but it seems most unlikely that they would be able to get anyone higher up the chain. Is the person who authorised the surveillance really likely to be extradited? It seems unlikely, so why bother?  [1] Spiegel Staff, ‘Probing America: Top German Prosecutor Considers NSA Investigation’, Spiegel Online, 20 January 2014,