Perhaps, as the article says, the impact is less severe than verbal harassment. However, there have been suicides related to cyber bullying, so that does not mean that this is not an issue and may be ignored.
Online people love to give their opinions about things but when they direct their opinions towards someone like in a topic, comments or chat then it no longer is just their opinion because they are trying to hurl insults. Funny thing about narcissists and self-centered individuals is they believe everyone values their opinion or input which isn't the case. On a personal level if I am to be insulted I have to first put some kind of value on your opinion which for a stranger there is no value on what they say.