I think you're missing the point. If someone gets off on being a dick to other people in any context, whether it's online or in person, then that person has a p

I think you're missing the point. If someone gets off on being a dick to other people in any context, whether it's online or in person, then that person has a psychological problem. They are under the impression that what they do online is not connected with "real life", and they enjoy being a dick to other people. Both of those things are very negative qualities for a kid to have (although not uncommon, because kids), but if someone still has both of those qualities as an adult then yes, it is absolutely a symptom of a psychological problem.