Sorry if I get too philosophical, but are they really criminals? In what way? Do they know that in this day and age it isn't moral to laugh at another's suffering, even if it is their only form of entertainment? Do not demoralize them for their misdeeds, but instead teach them the error of their ways in a constructive manner. Unless they are too deep in the trolling, we should all just ignore what we don't like instead of dwell on it. Negative thoughts only demean who we are as people. Do not wallow in it, let it make you stronger.