Defamation
Defamation is a false statement of fact that damages a person's or company's reputation; insults and slurs are treated similarly in many countries.
Versus criticism
Opinion and harsh criticism are protected; false statements of fact and gratuitous insults are not. The line depends on the facts.
Remedies
Civil claims, criminal complaints where available, platform reports and the right of reply. See the UK Defamation Act, German StGB 185-187 and Turkish Penal Code 125.
Frequently asked questions
Is there a time limit?
Yes, and it is short: one year in England and Wales, six months for a criminal complaint in Turkey.