The NSA's surveillance network can reach about 75% of US internet communications - which reports say is more than what US officials have disclosed.
The National Security Agency's (NSA) surveillance network has the capacity to reach about 75% of all US internet communications in the hunt for intelligence, says a report.
Citing current and former NSA officials, the Wall Street Journal reported on Tuesday that the 75% coverage makes up more of Americans' internet communications than officials have publicly disclosed.
The newspaper said the agency keeps the content of some emails sent between US citizens and also filters domestic phone calls made over the internet.
The NSA's filtering, carried out with telecom companies, looks for communications that either originate or end abroad, or are entirely foreign but happen to be passing through the United States, the paper said.
But officials told the Wall Street Journal the system's broad reach makes it more likely that purely domestic communications will be incidentally intercepted and collected in the hunt for foreign ones.
'Defeating foreign adversaries'
In response to a request for comment, NSA said its intelligence mission "is centred on defeating foreign adversaries who aim to harm the country. We defend the United States from such threats while fiercely working to protect the privacy rights of US persons."
"It's not either/or. It's both," NSA said in a statement to Reuters.
The newspaper said that these surveillance programmes show the NSA can track almost anything that happens online, so long as it is covered by a broad court order.
Edward Snowden, a former NSA contractor, first disclosed details of secret US programmes to monitor Americans' telephone and internet traffic earlier this season. – Reuters