The important thing about free speech is the imperative or cautionary speech, not necessarily the frivolous. In this regard, users would seek to defend their position while other forces seek to clamp down on them.

For example, if warning of martial law or impending doom; those that are criminals may not want anyone to be able to say anything. That is why reasonable websites need to remain for cautionary reasons, otherwise criminals can get away with the frivolity of sabotage.