User blog comment:Subject 9/Reasons/@comment-24.42.163.227-20110908040039

The reaper are a machine, obviously some built them, or construsted the thing that built them...my speculations on this are still sketchy, but assuming they were indeed built by someone or something, that same party likely programmed them. perhaps the programming was faulty, corroded/corrupted, or incompetely leaving the determination of the programing to a machine mind, built by a flawed organic being. from here we can take nearly thousands of routes, many which are played out in popular science fiction, such as Terminator, Halo, Matrix, ect. As to why they attack perhaps a misguided and overstepped attempt at self-preservation, perhaps a goal to organize a universe currently in the hands of chaotic organics, perhaps they were programmed to conquer and continue to follow said program, perhaps to bring peace by elimination of all potential 'threats' to said peace, or maybe they have come to believ as the geth suggest, that they are gods, experiment a little with each new rebirth of the galaxy, a deranged scientific race...