That's not censorship. It's Fb's and other social media's desperate attempt to appease new government to prevent strong legislation, such as being held liable for their user's content, forced real names, regulation, and breakup.
Yes, the question really is are they liable for the violence that's produced through their algorithms?
I'm sorry, but please justify or rephrase this. People chose to do violent things. Social media may indeed be an accelerant, but someone kept providing fuel and someone was asking "my kingdom for a match!" (or more accurately, "a match for my kingdom!"). And in response, a large number were prepared to provide matches and light fires.