Well i remember in school.. one teacher always used to shout abuse.. Particularly to some students.. They could do notin since the subjects marks were awarded by him.. After their final year and after they got all the marks certificate etc etc they all ganged up one day and made him cry....... If the other guys had not intervened they would have paraded him bare on the playground... But thas not a wise thing to do.. but atleast they made him learn a lesson...