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In fiction (and real life) hacking is the process of breaking into computers, robots, advanced artificial intelligences and/or software and taking control of the system. The process can be achieved through wireless connections or wired lines or through the addition of equipment (corrupted USB add-ons, nanomachines etc). Some fictions even extend the definitions into hacking things like reality or the human mind. In the latter case that would be a form of mind attack and the former is a form of reality warping. Hacking can also be described as a robot mind attack. Since robots are immune to conventional mind attacks hacking would be the next best thing.