Nothing in Snowden's leaks suggests that the government has access to your friend's email, let alone is reading it. Stop exaggerating to your non-techie friends.
I read the documents released by Snowden. Which leaks are you referring to? Can you point me to any document that suggests the NSA has his friend's emails?
Snowden leaks showed that they get billions of hits each month from the various submarine cables as well as direct access from telco backbone fiber stations in the US, Europe, Middle East, and elsewhere.
> As this map shows that almost 3 billion data elements from inside the United States were captured by the NSA over a 30-day period ending in March 2013, Snowden stated that this tool was collecting more information on Americans located within the United States than on Russians in Russia
So I'd say there is an 80-90% chance the NSA has a good chunk of his friends email. Closer to 95% if he was located outside of the US.
The only thing stopping them from getting the full content of each Americans (plus 3 hops) passive data collection (besides 100% of metadata they get legally) is a FISA warrant. They have no restriction for foreigners.
Maybe you need to reread some of those slides because you clearly missed the big picture.
Your single source does not actually collect his friend's data. According to Snowdon's leaks, it was used to find a court-ordered monitored target's traffic leaving or entering the country. It does not actually siphon all data, including emails, to the NSA.
MUSCULAR provides similar filtering capability within Google's and Yahoo's networks, though not anymore because they encrypt all traffic. Again, only metadata. And again, the email envelope collection had already been shut down prior to the leaks according to the leaked documents. According to Snowden's leaks, the NSA is not allowed to keep communications from a US citizen or anybody even living inside the US without a court order, so no, his friend's emails don't reside with the US government.
