For example, if you have piles of proof of someone committing a crime like sexual assault and the cops refuse to take it seriously, you can reliably post it on Twitter these days and people will take it seriously. In Japan, the person who committed the crime can reliably sue you for ruining their reputation and win. Stating actual plain facts about a person that harms their image on any public platform will land you in trouble, unless it’s something that’s clearly in the public interest to know (like if a company is putting arsenic in their baby food). It’s likely one reason why incidents of work harassment and abuse only become public after someone kills themselves.