A vast majority of the people identified in a large cache of online conversations intercepted by the National Security Agency were ordinary internet users, and not legally targeted foreigners, according to a Washington Post report.

The study was based on 160,000 emails and instant-messages and 7,900 documents from some 11,000 online accounts, intercepted by the security agency between 2009 and 2012 (President Obama's first term in office). The Post, which obtained the information from former NSA contractor Edward Snowden, took four months to complete the investigation.

The paper says that highly personal information such as medical records, pictures, and more, which had little intelligence value, was retained. "They tell stories of love and heartbreak, illicit sexual liaisons, mental-health crises, political and religious conversions, financial anxieties and disappointed hopes."

The investigation revealed that nearly half of the people in the intercepted conversations were US citizens or residents. Although more than 65000 references to personal information like names, email addresses, and more had been obscured, The Post did find nearly 900 additional e-mail addresses that could be strongly linked to US citizens or residents.

The investigation also revealed how security analysts deemed whether a person was a foreigner. Often times emails written in foreign languages, being on the IM “buddy list” of a known foreign national, or using an international IP address, were reasons enough to believe that a person was not an American.

While the report raises some real privacy concerns, it also confirms that these far-reaching surveillance efforts have led to discoveries of considerable intelligence value. These include "fresh revelations about a secret overseas nuclear project, double-dealing by an ostensible ally, a military calamity that befell an unfriendly power, and the identities of aggressive intruders into US computer networks". The publication didn't reveal specific details so as to avoid interfering with ongoing operations.

The news comes just a few days after it came into light that the NSA is targeting anyone who is interested in online privacy, specifically Linux Journal readers and Tor and Tails Linux users.