ABC's Nick Schirfrin reports: For the second time in three days, CIA drones attacked a target in North Waziristan — today firing a torrent of at least six missiles on a building and cars full of people trying to escape the initial attack. It was early afternoon when drones fired three missiles on a compound in Datta Khel — the same site of the largest ever drone attack (more than 16 missiles fired in one attack on Feb. 2). Shortly thereafter, a fourth missile destroyed a vehicle of presumed militants escaping from the scene. And not long after that, two more missiles destroyed two additional cars full of people escaping. The target is unknown, but it's most likely the Haqqani network. Some of you have asked us of late: what's the point? Why so many missiles? There's not one answer to either of those questions, and US officials give varying explanations. But they seem to agree on two things: the more leaders/mid-level leaders they kill, they believe they are eroding the leadership to the point where the successors become increasingly incapable. And secondly, they believe they are getting closer and closer to Siraj Haqqani, Taliban Target Number One these days. It's become clear the Pakistanis are protecting Siraj less than in the past, and the US has subsequently increased their pressure in North Waziristan, where his network is based.