The greatest damage done by the Snowden revelations has not been to US security. It has been to the US's reputation and supposed moral authority.
It has been interesting to watch the overseas reaction to the revelations, something most Americans probably are not aware of. The anger over the revelations and the delight in the flight of Snowden has been fascinating to watch.
On the lighter side it has been amusing to watch the media chasing of Snowden to the point where the plane that he is supposedly not on is filled with legions of reporters now going to Havana ... with no booze on the plane. Hah!