M F Whitaker asked a question which has since been closed because it asked for legal advice in a specific case. I believe that there are two questions of general interest in the closed posting. The second question is:
When do online insults become criminal defamation in Germany, and who initiates the prosecution?
The German constitutional court recently ruled on a technical issue regarding online defamation: Renate Künast can demand that social media companies provide information about certain users, which then allows her to proceed bringing a case against those individuals. While the ruling is not in a defamation case itself, but the findings of the constitutional court will become a guideline to other courts when they judge specific cases.
Can you summarize the current understanding of what is, and what isn't, defamation in a social media platform?