In the last four years, U.S. UAVs, generally using Hellfire missiles, have killed about a thousand people in Pakistan. Only ten percent of them were civilians, the rest were al Qaeda or Taliban members. That's with about 90 attacks, and nearly 90 percent of those have been in Waziristan, a small area near the Afghan border, largely controlled by the pro-Taliban Mehsud tribe, and the four other tribes that also support the Taliban. Most of those killed during these attacks were low level terrorists. But 14 were senior leaders, including the head guy for all the Pakistani Taliban (a Mehsud tribal leader.) The rest of the senior people were al Qaeda, and this made the al Qaeda even more paranoid about the loyalty of their Taliban allies. In the last few years, hundreds of al Qaeda members, most of them non-Pushtuns, have been killed by local Pushtun tribesmen. Some of these tribes were pro-Taliban, but all the killers were definitely hostile to al Qaeda.
The terrorists suspect that spies are providing information, given the widespread hostility towards al Qaeda among the Pushtun tribes. And there is growing hostility to the Taliban as well. This year, there have been many more armed Pushtuns going out hunting for pro-Taliban Pushtuns. If you can make a phone call, and later pick up a $10,000 reward (a lot of money in this part of the world), in order to kill one of your Taliban or al Qaeda enemies, why not just do it? This is one reason why terrorists are hostile to the introduction of cell phones in remote areas. Dozens of Pushtuns have been accused, and executed for such spying, but little proof has been produced. This has led the Taliban and al Qaeda to consider that all those UAVs up there (out of rifle range), and the unseen space satellites, were able to sort out who was who on the ground, and figure out when a group of people in a courtyard, a building or a SUV, were all terrorists. That's when the Hellfire missile would arrive. It's been disconcerting, and bad for morale. Which, if you are fighting terrorists, is a good thing.