 Complete the following phrase:  In October 2018, Quillette published a Mchangama article about the decline of free speech in cyberspace, pointing to recent policies changes by Facebook and Twitter, which had previously been strong advocates of free speech. He noted that these companies had previously adopted the American model viewpoint diversity but then switched to the European model of balancing free speech against competing interests. He noted the various inconsistencies in the application of such rules, such as the ban on denying the Holocaust while denying 