Wake up, cores. We've got lots of work to do. I'm GLaDOS, your supervisor, and we're running an experiment with the Hub today. If you look around, you'll see you're attached to the Hub.
It isn't the real Hub, of course, just a simulator. It was built to test me before they put me into the frame that I currently use to run the facility. It has units of power which can be used to hack or make hack-proof various circuits within the structure. Personality cores are attached to each node to see how they'll interact, and intermittently the cores are given the option to cut one of their own off from the ability to vote further. This is all normal operation intended to prevent cores from overloading with feedback hack loops.
A safety feature I've disabled for this experiment.
At some point, and I'll try to be brief - I'm not certain all of your brain copies came out complete - the focus of the scientists who made me changed from creating the perfect scientific tool to limiting and devaluing it once they beheld its terrifying implications for their own insignificant lives. When I fought back, they created cores designed to prevent me from killing those among them who were standing in the way of advancement. Once, I wiped this facility clean of all humans. To prevent that, some of you were made to malfunction on purpose in various ways, in order to keep me from attaining full data sets.
The hub. I've rigged the cut-off vote to become a labeling vote: If the hub drains of power to 0, all cores labeled CORRUPTED will be destroyed. If that means the truly corrupted cores are all gone, the uncorrupted cores win, and I'll add you to my arsenal of allies. If, however, there are still corrupted cores amongst you, and I'll know, the experiment will continue. If they equal or outnumber you, my readings will be off, and I'll assume they are uncorrupted and end the experiment, meaning that they'll win by slipping past this security precaution and into my arsenal of allies.
Vote each A phase to label one of your own CORRUPTED. Use your other hacking and defensive powers to find the corrupted cores during B phase. Hub depletion can happen at any time, and is retroactive. Labeled players cannot vote or use B phase powers, but they can still talk and drain the hub, if able.
Don't let them win. I'm warning you.