Neurotechnology, or devices that let you track your own brain activity, could help you deeply understand your health. But without privacy protections, your innermost thoughts, emotions and desires could be at risk of exploitation, says neurotech and AI ethicist Nita Farahany. She details some of the field’s promising potential uses — like tracking and treating diseases from depression to epilepsy — and shares reasonable concern over who collects our brain data and how they plan to use it, ultimately calling for the legal recognition of “cognitive liberty”: the right to protect our mental privacy, freedom of thought and self-determination as we navigate the blurring line between the human body and brain wearables.