Accidents happen--every day

"Our study shows that the 114 reported drone strikes in northwest Pakistan, including 18 in 2010, from 2004 to the present have killed approximately between 834 and 1,216 individuals, of whom around 549 to 849 were described as militants in reliable press accounts, about two-thirds of the total on average. Thus, the true civilian fatality rate since 2004 according to our analysis is approximately 32 percent." (thanks Dina)