A company is located in a physical place and has to follow the laws in that place.
I am 100% sure that if youtube started to reject all content from Muslims then they would get hit by a discrimination law suit and end up in court over it. The argument would be that google, youtube server, or the user is located in a physical place with anti-discrimination laws, and based on that users has rights.
As I mentioned earlier, my understanding is that as a corporation based in the US, Twitter is governed in part by Section 230 of the 1996 Communications Decency Act of 1996[1], which consists of the following:
"No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider."
How a conflict between Section 230 and hypothetical anti-discrimination laws barring a social networking from imposing a blanket ban on right-wing content should be adjudicated is way above my pay grade since I'm not a judge, let alone a lawyer.
To give an example of how the law sometimes work, Sweden has a similar law to section 230 called "The law regarding electronic billboards", which gives the provider legal space to operate as a intermediate without legal liability in regard to the message. During the Pirate Bay trial the founders argue that this gave them protection.
The prosecutor and later the court judgment cited a different law, one which was created in order to give the police the power to seize biker bars from organized crime. They argued that the website, just like a biker bar, allowed for "primarily" illegal activity and thus made the founder liable for operating it and gives the police the power to seize it in order to stop further crime.
Even if twitter, google or any other private operated website is not treated as the publisher or speaker, the operators can still be charged under any law that do not distinguish on the accused being the publisher or speaker.
I am 100% sure that if youtube started to reject all content from Muslims then they would get hit by a discrimination law suit and end up in court over it. The argument would be that google, youtube server, or the user is located in a physical place with anti-discrimination laws, and based on that users has rights.