Five key take-aways as revelations mount on worldwide U.S. spying A vast global surveillance program that monitored the private communications of millions of ordinary people - as well as dozens of world leaders - has led to strained friendships and sharp questions for U.S. President Barack Obama. On Monday, the Spanish daily El Mundo reported that the U.S. National Security Agency (NSA) was behind the monitoring of 60 million phone calls made in Spain in the span of one month. It is just the latest revelation - and unlikely to be the last - that started in early June when reports by the American journalist Glenn Greenwald started appearing in the Guardian newspaper. His source: former NSA contractor Edward Snowden, who had disclosed a trove of classified documents before fleeing the U.S. Here are five key take-aways from the drip-like and almost daily revelations. Invasion of privacy - at home and abroad Revelations in June that the NSA ordered the telecom company Verizon to hand over phone records of millions of Americans on a daily basis sparked a renewed debate over the extent of domestic spying in the U.S. But the allegations now go beyond U.S. borders and that the NSA collected phone records of 70 million French citizens and 60 million Spaniards. In the case of Spain, there is no suggestion that the content of calls were monitored. Instead, the NSA collected "metadata" - who was making calls, where the calls were made from, and what time of day the calls were made. Last week, Le Monde published details of a similar surveillance program of French telephone calls by the NSA - except the newspaper alleged that documents showed that conversations were sometimes recorded, but only when calls were being made from specific phone numbers. Strained friendships American ambassadors in Paris and Madrid have been summoned to answer the allegations that the U.S. government spied on millions of French and Spanish citizens. Meanwhile, delegations of European lawmakers and spymasters are already en route to Washington, D.C., to grill Obama administration officials and U.S. politicians. No politician has channelled a sense of betrayal the way German chancellor Angela Merkel has - and arguably for good reason. The allegation that her cell phone was monitored by the NSA - quite possibly for more than 10 years - was published last week. She told reporters last week that allies needed to trust each other and that "such trust now has to be built anew." President Obama was unaware - or so he says Reports detailing Mr. Obama's phone call last week with Angela Merkel state that the U.S. President apologized to the German Chancellor and said that had he known about any monitoring of Ms. Merkel's cellphone he would have ordered it to stop. Any suggestion that Mr. Obama personally authorized any surveillance would be deeply damaging. But that is exactly what a German newspaper alleges. Bild am Sonntag reports that Mr. Obama was informed in person about the surveillance of Ms. Merkel's phone by the director of the NSA in 2010. The newspaper cites a U.S. intelligence officer aware of the operation. But on Sunday, the National Security Agency denied the report. Whether or not Mr. Obama personally gave the green light to monitor Ms. Merkel's phone, the allegation initially reported by Der Spiegel remains damaging: weeks before Mr. Obama met his counterpart in Berlin over the summer, Ms. Merkel's cellphone was still on an NSA list of numbers for monitoring. Canadians are doing it too The classified NSA files obtained also reveal that the Communications Security Establishment Canada (CSEC), the country's electronic eavesdropping agency, had been involved in monitoring the communications of government officials at Brazil's Mines and Energy Ministry in 2012. Mr. Greenwald told the Globe and Mail that there were even more examples of Canada's surveillance program that had yet to be published. "There is a huge amount of stuff about Canada in these archives because Canada works so closely with the NSA," he said. Cooperation between eavesdropping agencies is not uncommon - especially among the five countries known as The Five Eyes: Canada, the U.S., Britain, Australia and New Zealand. Countries in the group have pledged not to spy on each other. There is no suggestion that the NSA surveillance program extended to monitoring the communications of Canadians. George W. Bush redux President George W. Bush ordered one of the largest domestic surveillance program just weeks after the 9/11 attacks. When the far-reaching phone data collection program came to light it was viewed by many Americans as excessive, invasive and a violation of their privacy. Mr. Obama, who campaigned in 2008 as a civil liberties presidential candidate, now faces the same questions and debates. "The request for the bulk collection of all Verizon domestic telephone records indicates that the agency [NSA] is continuing some version of the data-mining program begun by the Bush administration in the immediate aftermath of the 9/11 attack," writes Mr. Greenwald.