Washington Post 
Feb 21, 2011
CIA drone attacks in Pakistan killed at least 581 militants last year, according to independent estimates. The number of those militants noteworthy enough to appear on a U.S. list of most-wanted terrorists: two.
Despite a major escalation in the number of unmanned Predator strikes being carried out under the Obama administration, data from government and independent sources indicate that the number of high-ranking militants being killed as a result has either slipped or barely increased.
Even more generous counts – which indicate that the CIA killed as many as 13 “high-value targets” – suggest that the drone program is hitting senior operatives only a fraction of the time.
After a year in which the CIA carried out a record 118 drone strikes, costing more than $1 million apiece, the results have raised questions about the purpose and parameters of the campaign.