A new Apple patent describes AirPods that could read brain activity, which sounds alarming for privacy but is only a patent filing so far.

• Apple has patented AirPods that work as bio-sensing devices, using electrodes to read brain signals from the scalp.
• The concern is scale: Apple could end up monitoring the brains of over a hundred million AirPod users.
• Patents like this raise big privacy questions about companies collecting the most personal data there is — your brain activity.
• A patent is just a filing, not a shipping product, so no AirPods are reading your mind today.

Outlook: Expect more debate over "neural" data privacy as Apple and others push wearables that track the body ever more closely.