French authorities are shocked – shocked – to learn that the American government is spying on French citizens. The Foreign Ministry summoned the U.S. ambassador to the Quai D’Orsay to inform him that what’s going on is “unacceptable,” and President Francois Hollande claimed to have issued a stern rebuke to President Obama in a phone conversation.

At issue is the allegation – in a Le Monde article by Glenn Greenwald based on documents leaked by former National Security Agency contractor Edward Snowden – that the NSA carried out massive electronic surveillance within France, including collecting 70.3 million pieces of data on phone calls in a single month.

Naturally, the French would be outraged. Then again, it was revealed in 2010 that France conducts its own espionage activities here on U.S. soil. What’s more, French officials have been aware of the NSA program in France for months. Oh, and France’s intelligence agencies have established an electronic surveillance system of their own that monitors their citizens’ phone conversations, emails, texts and even their Twitter posts.

This is the way things work in the world we’ve been learning about from Snowden’s leaks. The latest lesson: Friends spy on friends. In recent years it’s emerged that the NSA has also been spying in Mexico, Germany and Brazil. Canada spied on Brazil. The U.S. spied on the United Nations. And there’s no reason to think it ends there.

The White House, embarrassed yet again thanks to Snowden’s revelations, now says it is reviewing the way the U.S. gathers intelligence “so that we properly balance the legitimate security concerns of our citizens and allies with the privacy concerns that all people share.” That’s a good start. There’s a whole lot to consider.