These boundaries don't appear to have anything to do with the First Amendment.
1) It explicitly constrains the US Government. 2) It implicitly constrains anyone who approximates the coercive power of the US government.
#1 is self-explanatory.
#2 implies that, in the US, anyone who attempts to use overwhelming coercive power of any form to silence speech tends to get looked on poorly by the law.
If Fetlife has a fraud rate that approaches normal and the banks cut them off anyway, it would be an interesting court fight.
In my opinion they have a lot to do with the First Amendment.
When a few big players can effectively and arbitrarily put someone out of business, that's quite a problem in my opinion.
When a few big players can effectively silence a voice, that's a free speech problem, in my opinion.
As our lives move from physical places to the Internet, I would like to see the same liberties maintained.
These boundaries have nothing to do with the first amendment.
Nowadays the right to free speech is enforced in a passive way, so-to-say: "Congress shall make no law [...] abridging the freedom of speech".
However the Constitution was written in a different era, when doing nothing to abridge the freedom of speech was effectively granting freedom of speech to everyone. Today on the Internet a few corporations can effectively abridge one's freedom of speech.
So, what I am asking is: do we need a stronger and active enforcement of the free speech rights? An active enforcement in which the Government mandates that all businesses must give equal voice to citizens?
Apparently that's not something new, see mfringel's comment above:
"#2 implies that, in the US, anyone who attempts to use overwhelming coercive power of any form to silence speech tends to get looked on poorly by the law."
Edit: guys, that's not Reddit, try not to downvote a civil debate.
Note that I am not taking any position on whether such a new right would be a good or bad idea. I am merely pointing out that what you envision is in no way within the scope of the existing First Amendement.
You are proposing not merely the active enforcement of free speech as such, but removing the existing longstanding right of private entities to determine what forms of speech they permit within privately owned venues, simply because some such venues happen to be large and popular.
This same argument was made 200 years ago when newspapers were the dominant mode of mass information exchange. The country decided then that the government ought not to regulate what newspapers must and must not print, and enshrined this in a constitutional amendment.
How is your proposal to regulate what private sector social media companies are required to publish any different in substance than a (clearly unconstitutional) proposal to regulate what private sector newspapers can and cannot publish?
I am talking about service providers, not users.
Suppose there's only one printing house in town and within a 1000 km radius. This de facto monopoly means that if you are denied their services you cannot publish a book.
My proposal is: we should mandate that the service provider (i.e. the printing house) provides the same services for the same price to all customers.
Of course that would require a definition of who will be considered a service provider, but I think that the FetLife controversy clearly shows that some freedoms are being endangered: outside the Internet no monopoly/oligopoly is so strong that can send virtually anyone out of business in a matter of a week.