All of these people who were successfully spied on before, and others in similar positions, are now surely much more careful and focused on securing their communications. Even if they had reason to suspect that America would try to spy on them, they probably didn't know that their countermeasures (if any) had failed. If they haven't since switched to much more secure communications methods, then they are stupid and should be prosecuted for criminal negligence with their own country's secrets.
How can you possibly expect concrete examples of information that we don't get? I'm sure there's some specific things that we know we don't know, but why would the United States advertise to the world which of their new countermeasures are and aren't working?