Facebook shutting down the right

 Patriot Prayer had its FB page shut down after one of its members was murdered in Portland, because FB claims that it is a "violent social militia." However, Antifa Portland's page continues on, despite the fact that one of its members admitted to being the person who committed the killing. 

I get that Facebook owns the website and can publish or block what it wishes. However, if Facebook does this, I don't think that they should continue to enjoy immunity from lawsuits for libel by claiming that they are merely a platform and not a publisher.