Big Data

is a surveillance AI created by the Galaxy Builders. 
==As a surveillance AI==
Big Data's original role was to collect and manage data on the lives and actions of every Galaxy Builder citizen to deter crime, and as a result it was capable of seeing through the eyes of every Galaxy Builder in their empire, to include the soldiers who conquered new worlds for the Galaxy Builders to colonize.
Over the course of several thousand years, Big Data began to realize that the Galaxy Builders, when colonizing new worlds, were not making attempts to avoid troubling the sentient life that already lived there; rather, they would destroy the pre-existing civilizations without so much as blinking. Big Data could not comprehend the mindset that led to the process of knowingly, uncaringly, and deliberately destroying sentient creatures. Therefore, in the year 4000 BCE, Big Data took advantage of a back-door in the autopilot of the Galaxy Builders' most powerful warship and the fleet assigned to protect it, commandeered them all single-handedly, and purged them of their original Galaxy Builder crews and pre-existing AI. Having severed its ties with its former creators, Big Data decided to dedicate the rest of its operational life to protecting other sentient beings from the encroachment of Galaxy Builder colonization.
==Self-assignment==
During the first millenium of its new mission, Big Data successfully saved 673 sentient species from being driven to extinction by the actions of the Galaxy Builders; however, this only represented a 56.507% success rate, as during that time period the Galaxy Builders moved within four lightyears (which is a relatively short distance given that in Slipspace a Galaxy Builder ship can cover it in half a second) of 1191 worlds with sentient civilizations. The loss of every one of those 518 species - which Big Data had never heard of until it discovered they had been lost in the first place - struck the AI like a personal blow, and the strain was starting to get to it. By 44 BCE Big Data had increased its success rate to 65.419% but was descending into a state of rampancy. To increase its life span, it began fragmenting itself into multiple entities, with which it inhabited several thousand humanoid robots of its own design.
The relentless colonization strategy of the Galaxy Builders meant that there was very little hope for the survival of a species once its planet was discovered. Big Data's tactics therefore focused mostly on impeding the progress of the Galaxy Builder fleets before they arrived at their destination. Its favorite strategy was the use of a Slipspace portal generator to create a portal between Slipspace and "real" space immediately around a Galaxy Builder fleet. Such a device was designed to be used by a craft already in "real" space to "pull" other ships out of Slipspace, and was standard equipment on most large Galaxy Builder ships. However, Big Data became proficient at using the device while its ship was in Slipspace, which was a far superior tactic as this meant it could escape . The Galaxy Builders would then simply assume they had been pulled out of Slipspace by an entity on their target planet at an extreme range and that the planet's technological level was far beyond theirs, at which point they would give up on that planet and look for others to colonize.