Interesting. Please go on.
The concept of "Free Speech" as an ideal has existed as far back as Ancient China and Greece, long before the U.S. Constitution was a thing. It's a basic human right and part of the Universal Declaration of Human Rights, signed and adopted by most democratic governments across the world:
Article 19 - Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.
You know what countries didn't sign it at the time? Totalitarian countries, who obviously had the ulterior motives. As a rule, I suspect
anybody who wants to restrict free speech (except in cases of actual, demonstrable harm) of having ulterior motives.
So what does this have to do with the Internet? It's fairly simple. Like it or not, big social networking websites are the successors to the town squares of yesteryear. Twitter, Facebook, Reddit and the like are communication mechanisms of unprecedented power. Benjamin Franklin and Thomas Jefferson could never have imagined being able to have instant communication with somebody living in Vietnam. Unfortunately, many of these sites are starting to show signs that they might start censoring.
A common refrain is that those concerned should take their business elsewhere. But the problem with this suggestion is that there isn't much choice. How many viable alternatives are there? Hardly any. It's not for lack of trying, either. Remember when Google tried to create their own social network? Remember how hardly anybody used it? That's because they had no incentive to use Google+, because everybody and their mother was already on Facebook. These companies have almost unprecedented power over communication. This is frankly unsettling, and why I think those who argue big social media platforms should be designated as "privately owned public spaces" have a point.
It's also disconcerting that we expect the free market to preserve freedom of speech. This is
really dangerous. Do we expect the free market to preserve racial equality? To preserve worker safety? To preserve the environment? To preserve product quality? To preserve the accuracy of advertising?
Finally, those who argue that corporations should have the power to censor speech they don't like should beware of this being used against
them. When free speech on the largest hubs of the Internet can be censored at the whim of a single CEO, everyone suffers.