Snowden, on the other hand, has exposed something even experienced observers did not take for granted: that the US government has created a massive apparatus for discovering everybody else's secrets. Under the cover of the "war on terror", it has been secretly trawling the telecommunications networks of the world for information on any other subject that affects its interests.
Never mind the hypocrisy - American secrets are sacred, but the United States has the right to know everybody else's. It's the scale and brazen arrogance of the operation that is so stunning. Exhibit A is the Prism programme, whose existence was a secret until Snowden spilled the beans last month.
This programme, run by the National Security Agency, began in 2007. It collects data from all nine major American internet giants - Microsoft, Apple, Facebook, Google, Skype, etc - and they are not allowed to reveal the fact they are passing the data to the US government.
In the first instance, it's mostly traffic analysis: who is talking to whom? But if the traffic pattern sparks the NSA's interest (or if the US government wants to know the content of the messages for other reasons), then the spies can read the messages. And, as you would expect, Prism didn't just stay focused on "terrorism" for very long.
The NSA started using its new tools, and some older ones, to spy on foreign governments and companies, including those of America's allies. "We hack network backbones - like huge internet routers, basically - that give us access to the communications of hundreds of thousands of computers without having to hack every single one," Snowden told the South China Morning Post .
US citizens resident in the United States are allegedly exempt from having their messages read without a court order (but the court is secret, too). Unless American citizens communicate with people living outside the US, in which case they are fair game.
Americans are remarkably untroubled by the NSA's actions. Almost a million people work in the US security industry, and most of those jobs would disappear if Americans did not believe that "terrorism" is the greatest threat facing their country. Foreign governments, by contrast, are very angry. The countries targeted by the NSA included not just obvious candidates such as China and Russia, but US allies such as France, Italy, Greece, Japan and South Korea.
But foreign protests will not force a shut-down of the Prism programme. At most, it will be renamed and re-hidden.
Manning and Snowden have done the world a service by exposing the US government's illicit actions, but Manning's future is probably life imprisonment, Snowden's a life in exile (if he's lucky). No good deed goes unpunished.
Gwynne Dyer is an independent journalist whose articles are published in 45 countries.