This is going to be some random thoughts on an issue I am riding the fence on. Generally I don't find modern life that different than that of Ptolemy's time so even with the internet I just draw on existing laws. This one has me though.
Assuming my website is not an absolute monopoly on something do I have to allow your posts?
If I own a bar I have to serve everyone, even Americans of German descent who can't prove they fought the fatherland in the great war. I don't have to let everyone have a microphone though.
If I own a business, lets say a church, I certainly don't have to let everyone speak. I probably have to let everyone in.
The town's square has to reasonably let everyone in and speak.
The internet sorta is public property, there are a lot of power cables and fibers laid across everyone's private property enabling me to have a website. Them posts are going on my server though.
Throw some more analogies at me from each point of view!
No you don't have to let everybody post on your website.
But let's not be too simplistic..facebook isn't just a *website*...nor is twitter.
These are monoliths that the entire world uses and they have no competition. If you get booted from twitter, there is no comparable system by which to tweet and be seen by the world. There is no comparable system by which you can reach out and speak directly to, say, the president...regardless of your locale.
And there is just nothing like facebook. It's the go-to for communication..whether it's sharing events, stories, pictures, selling things...nothing else compares and everybody is on board. People who are banned from facebook are being banned from speaking in the manner that most people speak.