What Happens Next | NSA Employee Flees to Hong Kong

The latest story from the Snowden documents analyzes a large cache of intercepted conversations -- actual operational data -- and concludes that 90% of the individuals eavesdropped on were not the targets of the surveillance.

Many of them were Americans. Nearly half of the surveillance files, a strikingly high proportion, contained names, e-mail addresses or other details that the NSA marked as belonging to U.S. citizens or residents. NSA analysts masked, or “minimized,” more than 65,000 such references to protect Americans’ privacy, but The Post found nearly 900 additional e-mail addresses, unmasked in the files, that could be strongly linked to U.S. citizens or U.S.residents.
[...]
Many other files, described as useless by the analysts but nonetheless retained, have a startlingly intimate, even voyeuristic quality. They tell stories of love and heartbreak, illicit sexual liaisons, mental-health crises, political and religious conversions, financial anxieties and disappointed hopes. The daily lives of more than 10,000 account holders who were not targeted are catalogued and recorded nevertheless.

Note that this is data that the NSA has repeatedly assured us that Snowden did not have access to.
Benjamin Wittes has a good commentary on this.