Everything runs on the IntoMind One and on the computer beside you, or on a small board. Nothing is sent over the internet.
Nothing is kept unless someone saves a file, apart from the custom AI head you teach in the Mind-Controlled Light Switch. It stays on the IntoMind One until it is removed or replaced. It holds no recording of your EEG, and it can't be copied off.
A saved file made from someone's EEG belongs to them. Keep it only with their permission, and delete it when the class is done with it.