For those that buy Oculus Rift headsets in the near future, you might want to start looking for metal contacts in the headband where it touches your skin.
In the most charitable case imaginable, users would be invited to enable the feature in software and experience mind control of their games, uav's, or whatever.
I envision this might end up like laptop lid cameras: there won't be a hardware disconnect switch for the feature so people will put tape over the sensor pads if they don't trust the hardware not to read their eeg.