Jason Koebler writes: 'Brainwave-tracking is becoming increasingly common in the consumer market, with the gaming industry at the forefront of the trend. "Neurogames" use brain-computer interfaces and electroencephalographic (EEG) gadgets like the Emotiv headset to read brain signals and map them to in-game actions. EEG data is "high-dimensional," meaning a single signal can reveal a lot of information about you: if you have a mental illness, are prone to addiction, your emotions, mood, and taste. If that data from gaming was collected and mined, it could theoretically be matched with other datasets culled from online data mining to create a complete profile of an individual that goes far beyond what they divulge through social media posts and emails alone. That's led some to develop privacy systems that protect your thoughts from hackers.'