That would be back in 2011, when Superman renounced his U.S. citizenship in front of the United Nations, saying that he was Earth's hero, and that being a champion of The American Way sometimes hobbled his ability to function in parts of the world where Americans are not generally welcome. You can see a key panel from that story, which appeared in Action Comics #900, at right.
The story took a beating in the fan press, and public figures including Fox News personality Mike Huckabee took aim to DC Comics, and Goyer, for his depiction of the Man of Steel.
Ultimately, the story just kind of...went away. It didn't serve as a springboard for more to come, and then the New 52 wiped out Superman's history entirely. Goyer, on the other hand, has had quite an influence on Superman and his perception in the eyes of the public, writing Man of Steel, which hit theaters today.
And in that film, when challenged by the U.S. military who ask what they should do if Superman should ever prove a danger to America's interests, what's the hero's response?
"General, I grew up in Kansas! I'm about as American as it gets."
So we've got a new generation, a new Superman...but "Truth, justice...all that stuff" apparently remains intact.