@Walter Hinteler,
If you remember Pollard, he was in the U.S. Navy but was passing along classified material to Israel, he is still in prison despite the efforts of Israel to have him released to them. If Germany finds a German citizen passing intelligence to any other country, I'm sure that person will also be tried in German court, probably will serve time.
It wasn't that long ago, that East Germany was obsessed with spying on West Germany. The word spy creeps everybody out, however, as much as I hate to quote Saint Reagan, we all need to trust but verify. Spying is neither good or bad, it's necessary for all nations to protect themselves from surprise invasion or organized criminal activity. Germany and the United States have cooperated in exposing or arresting terrorists. Our two nation cooperate in many other ways, but if anyone thinks that Germany or other NATO countries don't spy on the US, you are sadly mistaken. The rationale is not to overtake or dominate the other countries, it's more a matter of national security for each and every nation. It would be incredibly irresponsible for Germany not to keep an eye on other nations, the German citizens deserve to be protected. So do the citizens of the United States.