The outrage is not because NSA spies on foreign governments. The outrage is because the context of the spying.
If a diplomat get caught spying, he gets deported. If the offending country continues, then the embassy might get closed. If a non-diplomat get caught spying, he gets jailed. Those are the common tools in dealing with spies.
The outcry happens when the spying is on neutral grounds like the European Union offices, or the spying is done in intrinsic globally shared common resource like the Internet. Problem is, the previous tools are not suitable. You can't really kick out U.S. from ever enter the European Union offices as soon the U.S. is found to be spying. Nor can you isolate the U.S. from the Internet when the U.S. is found to be spying there.
If a diplomat get caught spying, he gets deported. If the offending country continues, then the embassy might get closed. If a non-diplomat get caught spying, he gets jailed. Those are the common tools in dealing with spies.
The outcry happens when the spying is on neutral grounds like the European Union offices, or the spying is done in intrinsic globally shared common resource like the Internet. Problem is, the previous tools are not suitable. You can't really kick out U.S. from ever enter the European Union offices as soon the U.S. is found to be spying. Nor can you isolate the U.S. from the Internet when the U.S. is found to be spying there.
Thus the political outcry.