You hear a lot about “free speech” and the First Amendment in connection with online forums like Twitter and Facebook. But “free speech” is the wrong way to think about them.
The First Amendment applies strictly to government, not private companies. Even then it’s not absolute, there are still limits to what you can say. On the other hand, private entities like Twitter and Facebook are free to determine for themselves what you can and cannot say in their domains. That determination has proven to be difficult, especially for Twitter. To make it worse, they find themselves criticized equally for removing abusive posts and for not removing them.
In the end, as the article suggests, it’s up to the Twitters and Facebooks to establish guidelines that reflect their communities and do the least amount of harm to everyone. It won’t be “free speech” in absolute terms, but it will be “free enough speech”.