What are the limits of Freedom of Speech in Social Networking

In Social Networks (like Ecademy) members are often demanding their right to speak feely - to "say it as I find it" - on matters. Often those demand are defended on the grounds of Freedom of Speech.

In this globally connected internet world we need to take notice of local laws and traditions as well as cultural diversity. More than that, we also keep aware of them as the restrictions on Freedom of Speech change for reasons of political expediency and social necessity.
When we write in some forums there are also local rules and codes to keep in mind and some take a narrow and some a wide view. But how can we know, as our content is distributed around the world via search engines and mirror sites, what should we aim for? What is better?  - a narrow freedom or a wide one?