"Spying on your friends - that's really not on." That's how German Chancellor Angela Merkel reacted when she discovered her mobile phone had been bugged by American spies in 2013.
So claims that her country's own secret service spied on its European neighbours on behalf of the US have caused embarrassment and outrage in Berlin.
For years Germany's BND intelligence agency has worked with the US National Security Agency (NSA).
The NSA gives German agents a list of "selectors" - mobile phone numbers and IP addresses - which it wants the BND to monitor. The aim is to combat global terrorism.
But in 2008 the BND reportedly told the chancellery that the list of selectors now included targets that had nothing to do with terrorism. Among them, it is claimed, were European businesses such as Airbus.
Now, according to leaked documents, it appears Germany also spied on the French presidential palace, the French foreign ministry and the EU Commission at the behest of the NSA.
In the firing line
No public reaction has yet emerged from France but the revelation is bound to be damaging to what has been a sound relationship between the two countries.
There is mounting pressure on the German government to disclose how much it knew about the espionage.
In the firing line is Interior Minister Thomas de Maiziere, who in 2008 was the minister in charge of the chancellery and directly responsible for the BND.
He insists he knew nothing about malpractice within the secret service.
Tabloid newspaper Bild printed a picture of Mr de Maiziere on Wednesday- his nose elongated to Pinocchio proportions.
"Herr de Maiziere!" the accompanying headline screamed, "You lie with impunity!"
Mr de Maiziere says that - because the information is all classified - he is unable to comment publicly. But he has called for the leaked report to be presented to a special parliamentary committee "the sooner the better".
That committee was set up to investigate revelations by US whistleblower Edward Snowden about NSA surveillance in Europe, including the monitoring of Mrs Merkel's mobile phone.
On Thursday morning one of the committee's members expressed frustration. Christian Flisek, of the Social Democratic Party (SPD), said the committee had been trying to get a list of NSA selectors through official channels for weeks.
Surveillance is a sensitive subject here and the latest spying revelations have dominated headlines for days.
It is not so long, after all, since citizens of former East Germany were routinely spied on by their own government.
Angela Merkel's spokesman maintains that the chancellery was unaware of the extent of the espionage.
That has not stopped the questions.
Another German newspaper has devoted its front page to a "wanted" poster.
Who's the culprit, it wonders. And among the mug shots of politicians and civil servants - Chancellor Angela Merkel herself.