Subsidiarity
Each person must remain in control of his/her own data; the prerogatives of legal entities (trusted third parties, the State, etc.) must be limited to what is strictly necessary for the proper functioning of the ecosystem.
Decentralization
No person should be assumed to be incorruptible, and no protection should be assumed to be unbreakable; only the multiplication of involved third parties and the diversity of their interests can avoid flaws in a system of permissions.
Auditability
Sensitive devices, such as recording systems, can only gain the full trust of society by allowing any competent citizen to inspect their hardware and software aspects; for example by leaving the code open-source, and by physically disconnecting the sensors (camera, microphone, antenna...) when not in use.
Fair notion of privacy
This balanced concept is opposed to spying on innocent citizens as well as to an anonymity which would give full impunity to criminals. For example, it uses pseudonymity to hide the identity of individuals, while leaving the possibility of unmasking them in case of wrongdoing.