This topic has come up in many places, many times, and rather often recently in my life. I keep finding it being used to justify speech that in whatever venue is just not appropriate, or where it is just obviously hate speech. In the US, Freedom of Speech is not an absolute, and only applies to the government and governmental agencies. Let's actually look at the text of the first amendment.
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
This is probably one of the most important amendments to the US constitution as it really is the basis of all our freedoms. There has been some narrowing of this over the years, and these limits are generally for public safety, such as shouting "FIRE" in a crowded theater, or hate speech which is obviously meant to incite violence. This is the government we are talking about though, this is not any private situations.
What people often forget about this freedom is that there is a flip side to it. You can say whatever you want, but that does not mean that I have to listen to you, or that I have to give you a platform to make the speech. Just because we have the freedom from the government from stepping in and saying that you cant say X, that does not mean that you can still say it everywhere. As an example, you're in a gay couple's home and you come out with highly homophobic speech, or you're in a black person's home and you come out with racist comments, do you think that they don't have a right to kick you out of their home? They surely do, and you can protest freedom of speech all you want, but nothing illegal was done.
This also applies to the internet. Think of Facebook, Instagram, Reddit, or any other virtual meeting place as private homes. Saying things in there that insult or go against what the owner of that page in their space (aka their home) gives them every reason to remove you and your content from it. This is not government running amok and kicking you out, this is the owner of the page exercising their right to not listen to speech that they don't agree with. This is even more justified if the place has some kind of code of conduct, or moderation policy in place. This concept came into being very early in the days of the internet. This is the way that internet "trolls" are kept in check.
Is this censorship? Yes, it surely is. This is also about being a good guest. If you are not being a good guest in someone's home, they should remove you from the home. The same applies to the virtual home on the internet. If you don't follow basic social norms, or you break established rules, expect for them, as private citizens, to react by removing the offending post or kicking you out. You are breaking the rules of hospitality. Cry censorship, or freedom of speech all you want. It does not matter. You broke *ghosti-, and the hosts of the venue have every right to remove you.