Banning a specific portion of a speech is not censorship.

That's a baffling assertion.

There's no inherent human right to be on Twitter, access its contents or contribute to new content. It is private property and you give away the rights to publish your speech, as per their site policies. So removing content or accounts, is not by law censorship in such an arrangement. That people freely choose to use such arrangements and contribute to others' private property, is questionable.

It's a difference on how you view human rights. There are people that think not allowed access to the Internet human rights violation. I think not being allowed to post on twitter because you have an unpopular opinion is a violation of free speech.

A law can be added to protect this right like the right to be forgotten. We didn't think the right to be forgotten was even a right that is valuable to protect but here we are.

There's no right to a platform for free speech. Maybe there should be, but what that should mean is very difficult to assess. Taking a stab at platforms just because they're popular, isn't necessarily fair game.

Twitter and other social media are moderated in several ways. If your opinion is unpopular, it'll likely not be retweeted much, it may be moderated down by users and moderators, your account might even be banned. Private platforms are private, and regulating them would hinder freedoms to create and maintain diversity of such platforms in the future, ie. hinder competing platforms and innovation.

If such platforms become detrimental to society, that of course need to be addressed in some way. Right to be forgotten is a good example trying to balance out some of the imbalances.

It is. The supreme court saw that banning nudity in theaters, thus banning specific portion of speech in specific places is not infringing first amendment.

You have your freedom to enjoy nude in your home but not in theaters due to city regulations. That doesn't mean that the city is censoring.

You're confusing "the censorship is legal" with "the censorship is not censorship".

I don't treat control of the speech that does cross the lines of the first amendment censorship because if it's not protected by the first amendment it's a violation of the law thus it's an act of justice.

Similarly we don't call stopping robbery and murder censorship of our acts.

Pornography is pretty clearly not a violation of the law, so why do you consider Gab's censorship of it not to be censorship?