describes a punitive measure/punishment that is overly harsh in relativity to the crime or transgression. Normally done for the purpose of making an example for others to deter them from doing the same. Also issued out of fear/anger by an authority.
After Colombine, an elementary school principal was criticized for doling out a year's suspension to a student who used a toy pistol while playing cops and robbers. Many say that the punishment was draconian and reactionary on the part of the principal.