The National Security Agency has a much deeper role in the CIA's drone program in Pakistan, with new documents leaked by Edward Snowden showing a much more sophisticated and efficient targeted killing program than previously known, The Washington Post reports.

The controversial CIA program of using drones to target terror suspects in lieu of capture began in 2004 as the agency came under fire for their detention and interrogations of terror suspects. As Rolling Stone put it, they got out of the prison business and "into the assassination business."

The NSA has offered a big helping hand with a secret unit called Counter-Terrorism Mission Aligned Cell, or CT MAC, providing intercepts inside Pakistan of emails, phone calls, and "targeted network penetrations" — aka hacking.

From The Post, which detailed the tracking of Hasan Ghul, an associate of Osama bin Laden:

In the search for targets, the NSA has draped a surveillance blanket over dozens of square miles of northwest Pakistan. In Ghul’s case, the agency deployed an arsenal of cyber-espionage tools, secretly seizing control of laptops, siphoning audio files and other messages, and tracking radio transmissions to determine where Ghul might “bed down.”

The e-mail from Ghul’s wife “about her current living conditions” contained enough detail to confirm the coordinates of that household, according to a document summarizing the mission. “This information enabled a capture/kill operation against an individual believed to be Hassan Ghul on October 1,” it said.

While another major leak courtesy of ex-NSA contractor Edward Snowden, the collaboration between the two intelligence agencies doesn't come as a huge shock. In essence, the people that can grab foreign phone calls and emails are doing their job (the NSA) and feeding it to the guys that need that info the most (the CIA).

It seems that CT MAC is just the latest iteration of a unit known as GEOCELL, which was previously reported in 2005. That unit put people from different intelligence agencies in the same rooms to share information, and "rushed real-time tips warnings to field operatives as well as White House officials," according to the Los Angeles Times.