The idea
Anyone should be allowed to write, speak, and publish (through whatever means or media) their opinions and ideas. For example, if a person thinks the Earth is flat, that person should have every right to express and publish such a notion, even if it offends someone. Furthermore, even if a person has an idea or opinion that seems "dangerous" or "could incite hatred", that person should have every unabridged right to publish, disseminate, discuss, and proclaim that idea. This freedom would not extend to allowing death threats or harrassment or extortion.
Until we can proclaim what we think, we will never be free in this nation or anywhere else!
Think about citizens of USA–they can quite freely express, publish, discuss, and share opinions and ideas, even if such material is bogus or hateful or scary to some people.
Why is it important?
Because we have an unalienable right to express our ideas and opinions without fear of persecution. But governments here and elsewhere are driven by cowardly groups fearful of dangerous ideas and opinions. WE ARE ALL POLITICAL PRISONERS IN THIS NATION. If you need proof: http://en.wikipedia.org/wiki/Freedom_of_speech_by_country#United_Kingdom