This book explores how AI systems trained on neurodata are redrawing the boundaries of dignity, autonomy, and legal personhood. It reveals the emerging reality of NeuroAI: a world where machine-learning models anticipate our thoughts before we have even formed them. As neurotechnologies evolve, AI systems move beyond interpreting brain signals in labs and headsets to harvesting neurodata (whether extracted through direct interfaces, inferred from everyday behaviour, or reverse-engineered via predictive modelling) from users who never consented or even knew they were being monitored, transforming the subconscious into a commodified dataset. Drawing on case studies from criminal trials, law enforcement, and consumer technologies, the book reveals how Big Tech and platform operators increasingly treat neurodata as a resource for monetisation. Across the EU and the USA, emerging AI and data-protection regimes, including the EU AI Act and GDPR, as well as the US Fourth Amendment and HIPAA frameworks, offer incomplete or inconsistent safeguards against NeuroAI trained on neurodata to model and predict thoughts, emotions, or intentions, leaving cognitive inference primarily in a legal grey zone. Indispensable for legal scholars, technologists, and regulators, this critical roadmap illuminates the gaps in current law and identifies the safeguards needed to protect our most intimate inner lives. In a future where thoughts can be inferred, monetised, and weaponised without ever accessing the brain directly, this book shows us where the law must catch up before our minds, our rights, and our freedoms are turned into the next frontier of exploitation.