AP:

A court on Friday fined a 15-year-old schoolboy for posting a video on YouTube of his teacher singing karaoke without her permission and claiming she was a lunatic.
In the first case of its kind in Finland, Nurmes District Court found Toni Vesikko guilty of intentional defamation and fined him $120. He also was ordered to pay $1,000 in damages for “causing harm and suffering,” and $3,000 in court costs.

Just because she sings at a party does not give people permission to publish video footage without her permission. I don’t think it’s possible that anyone would think the “lunatic” claim was factual, but it still exposed her to ridicule. This is a very different thing from posting a video of a public figure, or yourself.