On eve of G8 Summit, a stunning revelation from Ed Snowden that British spied on delegates at 2009 London G20 summit (UPDATED)

The (U.K.) Guardian broke the story; the stunner is that "There have often been rumours of this kind of espionage at international conferences, but it is highly unusual for hard evidence to confirm it and spell out the detail." Hard evidence is exactly what Edward Snowden provided the Guardian.

Note from the report (opening paragraphs below) that the British government didn't only spy on government delegates from countries that have tense relations with the U.K.; it also spied on allies, even those in NATO!  Such a gracious host. 

As to what any of this spying had to do with keeping British citizens safe from terrorism -- nothing.

GCHQ intercepted foreign politicians' communications at G20 summits
by Ewen MacAskill, Nick Davies, Nick Hopkins, Julian Borger and James Ball
The Guardian
Sunday 16 June 2013 15.46 EDT

Foreign politicians and officials who took part in two G20 summit meetings in London in 2009 had their computers monitored and their phone calls intercepted on the instructions of their British government hosts, according to documents seen by the Guardian. Some delegates were tricked into using internet cafes which had been set up by British intelligence agencies to read their email traffic.

The revelation comes as Britain prepares to host another summit on Monday – for the G8 nations, all of whom attended the 2009 meetings which were the object of the systematic spying. It is likely to lead to some tension among visiting delegates who will want the prime minister to explain whether they were targets in 2009 and whether the exercise is to be repeated this week.

The disclosure raises new questions about the boundaries of surveillance by GCHQ and its American sister organisation, the National Security Agency, whose access to phone records and internet data has been defended as necessary in the fight against terrorism and serious crime. The G20 spying appears to have been organised for the more mundane purpose of securing an advantage in meetings. Named targets include long-standing allies such as South Africa and Turkey.

There have often been rumours of this kind of espionage at international conferences, but it is highly unusual for hard evidence to confirm it and spell out the detail. The evidence is contained in documents – classified as top secret – which were uncovered by the NSA whistleblower Edward Snowden and seen by the Guardian. They reveal that during G20 meetings in April and September 2009 GCHQ used what one document calls "ground-breaking intelligence capabilities" to intercept the communications of visiting delegations.

This included [...]

There's much more to the Guardian report.