The European Union's top court has ruled that Facebook can be forced to remove posts worldwide if they are considered illegal in one EU member country.
The decision by the European Court of Justice cannot be appealed.
The ruling stems from a lawsuit filed by Eva Glawischnig-Piesczek, former leader of Austria's Green Party, who wanted Facebook to take down insulting comments posted about her. An Austrian court found the comments violated the country's defamation laws.
Most social media platforms like Facebook usually remove content in any country where it is deemed unlawful. Thursday's ruling will force them to do so worldwide.
"EU law does not preclude a host provider like Facebook from being ordered to remove identical, and in certain circumstances, equivalent comments previously declared to be illegal," the European Court of Justice said.
Facebook quickly hit back at the ruling, saying it "undermines the longstanding principle that one country does not have the right to impose its laws on speech on another country."
Critics of the ruling have argued it would force internet platforms to use automated content filters that would not be able to distinguish between hate speech and satire.