>>5
According to an eastern belief (≒ a kind of metaphor), a triad of spywares called 三尸 ( or 三虫 ) is previously incorporated into the body of each human being on the earth.
And, ① the actions, ② the talked contents, ③ the thoughts & e-motions of each human being are recorded on 三尸 respectively, furthermore the recorded in-formations are sent to a celestial governor through 三尸.
If the celestial governor has a patho-logical and/or irrational rather than tolerant and/or rational mind, functions of 三尸 can bring nightmares ( bad dreams ) to us in some sense.