Great primer from ProPublica on the recent NSA leaks and what the agency can do with our data:
Q: What if I’m not an American?
A: All bets are off. There do not appear to be any legal restrictions on what the NSA can do with the communications of non-U.S. persons. Since a substantial fraction of the world’s Internet data passes through the United States, or its allies, the U.S. has the ability to observe and record the communications of much of the world’s population. The European Union has already complained to the U.S. Attorney General.