I agree with you for the most part, but I also think that we can expect organizations above a certain size or influence to have a bigger moral obligation than t

I agree with you for the most part, but I also think that we can expect organizations above a certain size or influence to have a bigger moral obligation than the little players. Unlike law, morality is a gradient. It doesn't sound unreasonable to say that the more power you have to shape the world around you, the more obligation you have to use that power for the greater good. This kind of noblesse oblige is not a foreign concept to most people. It might also make a difference if a company is actively trying to become the platform for everyone to express their thoughts. Whether or not your actions actually impede free speech or not depends a lot on whether or not there are alternatives of a comparable size and influence. For example, I have no obligation to let random people put up "TRUMP 2016" signs on my lawn, because they are free to put up signs on their own lawns, windows, cars, etc. But if all the HOAs in the city banned election signs, that could be a problem even though HOAs are not run by the city. The closer you are to having a monopoly on deciding what people can or can't say in their daily life, the more your moral obligations will resemble that of a government. This becomes so extreme in the case of the government itself, that smart people in the past have decided to codify some of the government's moral obligations into a legally binding document.