This week the continuing exposés on the U.S. National Security Agency’s covert surveillance programmes raised alarm among civil liberties groups and human rights advocates when a report suggested that the Agency is extensively involved in President Barack Obama’s “targeted killing” programme using drone strikes.

Citing documents made available by whistleblower Edward Snowden, a report in the Washington Post on Thursday said it was the NSA’s eavesdropping on e-mails that led to the killing of Hassan Ghul, an al-Qaeda associate who provided “a critical piece of intelligence that helped the CIA” find Osama bin Laden, in a drone strike in Pakistan’s tribal belt in October 2012.

The NSA trawls through millions of “innocuous e-mails” such as those sent every day by spouses with updates on the situation at home, and it was in one such e-mail that the agency came across intelligence on Ghul, the Post report said.

The e-mail from Ghul’s wife “about her current living conditions” was said to contain a sufficient level of detail to confirm the coordinates of their household, according to a document summarising the mission, and “This information enabled a capture/kill operation against an individual believed to be Hassan Ghul on October 1.”

While the U.S. Congress has grilled the intelligence community — including Director of National Intelligence James Clapper and NSA chief Keith Alexander — on several occasions since Mr. Snowden’s revelations, the continuing ambiguity on guidelines followed by the NSA — in principle supplied by the Foreign Intelligence Surveillance Act (FISA) Court — has caused consternation among civil liberties groups.

In comments made to The Hindu, Hina Shamsi, National Security Project Director at the American Civil Liberties Union, said the Post’s report underscored “how little we know about both the CIA’s targeted killing programme and the uses for information collected by the NSA”.

Ms. Shamsi added that it was impossible for the public to evaluate the rules that the government had set up for itself if it insisted on keeping virtually every aspect of them hidden.

“One thing we do know from credible media reports is that the targeted killing programme has killed thousands of people, including many hundreds of civilian bystanders, yet there has been virtually no transparency about who has been killed, why, and under what rules,” she said.

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