Social Media and Free Speech

Courts have ruled, you cannot yell fire in a movie theater for the fun of it.  So, what responsibility do social media web sites have when we see these sites being used by radical Islamic groups to make contact with each other by encouraging terrorism?  Will social media sites set up aggressive reviews of their sites to prevent this from happening as best they can do or will they claim privacy is paramount over life?  This is going to be a tough discussion by all involved.   FBI, Congress, DHS and local law enforcement.  Our constitutional rights vs. government.  When you surrender something to government, in all probability, you will never get it back, unless Congress passes a limited law that is acceptable to all with a closure date.  A tough dilemma to resolve.