Techniques for patterned and correlated electrical activity include receiving user data from a device of a user and anonymized data from other devices of other users, the user data and the anonymized data being received based on the device and the other devices having been co-located. The user data is compared to the anonymized data according to an activity. It is determined that an event occurred based on one or more deviations of the user data from the anonymized data according to the activity, the event being related to a health of the user.