In the future, brain-computer interfaces–implanted or external devices that allow the human brain to directly interface with computer systems and networks–have the potential to create massive shifts in both medical and non-medical fields, as well as have great implications for privacy, human intelligence, and how we interact with technology. This technology could allow people to use prosthetics that give complete feeling and dexterity to their users. It could be a way to cure paralysis and may even be able to remove chronic pain. Further in the future, brain-machine interfaces may give us access to fully immersive virtual worlds that are nearly indistinguishable from reality. In addition, these devices could allow for knowledge to be added directly into the brain in a very rapid manner, allowing humans to become vastly more intelligent. However, there are also risks that come with this technology. Privacy could be threatened, as companies and unscrupulous individuals could retrieve information directly from your brain. This could lead to intrusive and targeted advertising as well as blackmail depending on the nature of the information retrieved. There are also other threats such as hackers who could attempt to use brain-computer interfaces to bring harm to their users. Even the users of these technologies could be a threat as an unregulated and highly immersive virtual world grows and becomes accessible to anyone with an implant. New forms of harassment could appear, as well as abuse and exploitation in the virtual world. And that’s all without mentioning the possibility of governments using this technology to monitor their citizen's every thought. While this technology will have a great impact on humanity, it will be up to us to decide whether that impact is positive and beneficial, or negative and potentially even dangerous.