The ruling (linked in TFA) is conveniently written in English. It is pretty scary stuff, but IANAL - any professionals out there want to comment?
First of all, the comments made to the article in question "were vulgar in form; they were humiliating and defamatory and impaired L.’s honour, dignity and reputation. The comments went beyond justified criticism and amounted to simple insults."
Here is one of the more egregious comments: "What are you whining for, knock this bastard down once and for all [.] In future the other ones ... will know what they risk, even they will only have one little life.". Others were just name calling.
This is where the European Charter of Human Rights gets it wrong, because it allows exceptions to freedom of expression for a huge array of possible reasons. In this case, presumably, "for the protection of the reputation...of others". Seems to me, if you can outlaw simple insults, and vague threats, you can outlaw essentially anything.
In any case, the case was appealed all the way to the ECHR. While the ECHR says some of the right words in their appendix - they're all worried about censorship - none of that has any legal relevance. The core of the actual ruling:
"Based on the concrete assessment of the above aspects, taking into account the reasoning of the Supreme Court in the present case, in particular the extreme nature of the comments in question, the fact that the comments were posted in reaction to an article published by the applicant company on its professionally managed news portal run on a commercial basis, the insufficiency of the measures taken by the applicant company to remove without delay after publication comments amounting to hate speech and speech inciting violence and to ensure a realistic prospect of the authors of such comments being held liable, and the moderate sanction imposed on the applicant company, the Court finds that the domestic courts’ imposition of liability on the applicant company was based on relevant and sufficient grounds"
tl;dr: The news company should have pro-actively moderated comments and immediately - without any court case being required - removed the illegal comments. The court then goes on to express hope that this does not introduce a new reign of censorship, but that is exactly what is may do.