German student Sebastian Hahn helped run a server in Germany's southern city of Nuremberg which was used for the global Internet portal Tor. By routing search requests or e-mails via multiple encrypted servers, Tor allows users to stay anonymous, and hides their true whereabouts. Hahn's server was exceptional in that it helped administer thousands of other Tor servers.

Many people who want to protect their privacy online make use of Tor. For those living under a dictatorship or otherwise oppressive government, tools like Tor are crucial - as it's forbidden to even Google terms like democracy or press freedom.

According to research by two German public broadcasters, WDR and NDR, the NSA observed Hahn's server to the extent that everyone who used the server automatically landed on the surveillance agency's spy list. As a result, anyone intending to hide their tracks - or even test the Tor service - would be caught in the NSA's surveillance net.

Needless to say, the revelation has caused outrage among Germans, who due to their history including the Stasi and Gestapo are particularly sensitive to such topics.

NSA operation hardly a surprise

However, Helmut Aust - an expert in international law teaching at Humboldt University in Berlin - said the revelation hardly came as a surprise. It's exactly "the logic of intelligence operations to take a closer look where messages or content is encrypted," he said.

The NSA assumes that people who encrypt data have something to hide

This view is shared by intelligence expert Erich Schmidt-Eenboom. He says the "idea of this collecting mania by intelligence services is: 'Who encrypts has something to hide.'"

It's nothing new that the NSA aims to collect encrypted content. And Schmidt-Eenboom says it's also nothing new that the agency is capable of doing that: "Just a couple of years ago, long before [Edward] Snowden's revelations, specialized press reported that the NSA can filter encrypted information out of data streams, and decrypt that if needed."

And if they are able to do it, then they will. Especially with a tool like Tor: "They are downright furious when someone offers assistance for making online data traces anonymous," Schmidt-Eenboom said.

Whether the acts performed by the NSA are legal or not is hard to say, according to Aust. He says it's not clear where the crimes - if they can be considered crimes at all - have been committed. "In order to analyze this under international law, one would have to know where the Americans accessed this data."

New laws won't stop spying

And it's hard to believe that intelligence services would allow a mere set of laws hinder their work, Aust said. "It would be naive to believe that rules per se would completely stop intelligence measures."

And even if the spies were put on trial, prosecutors are not likely to be successful in court. "The US would seek to legally maneuver to prevent having NSA employees appear before a German court," he said.

If a foreign intelligence service did in fact spy on German citizens, it would potentially have violated laws. Yet, that's actually what it was created for.

German Chancellor Merkel's phone was tapped as well

And what did the German secret service (BND) do about this? Among its tasks is to protect law and order in Germany - which includes upholding Germany's constitutional right to telecommunications secrecy. The German agency obviously did not do a good job in that regard.

Or, perhaps it didn't do a good job because it didn't want to meddle in the first place? Admittedly, this possible scenario is pure speculation - as security service operations are by nature kept secret.

Germany-US cooperation

Schmidt-Eenboom points to close ties between German and US agents: "There's extremely close cooperation between BND and NSA. And, in many aspects, the BND is very much dependant on technical assistance from the NSA."

For that reason, one shouldn't expect too much from the German agency when it comes to getting to the bottom of this affair. "It's not in its interest to come down hard on its great brother," Schmidt-Eenboom pointed out.

However, the topic is likely not likely to peter out - not right away, at least. The federal prosecutor won't repeat his previous mistake of taking action only after public pressure. That's what happened when the news broke that Chancellor Angela Merkel's phone had been tapped. Schmidt-Eenboom said this won't be repeated: "He is going to investigate this case of his own accord."

But this may not yield results. If the German government were to see "vital interests of the Federal Republic of Germany at stake," it could stop investigations at any point. And Schmidt-Eenboom is convinced that the government is going to do just that.