I wasn't referring to you but to Gab. Gab certainly does contain Nazi and racial supremacist imagery.
No one is silencing anyone, all we are talking about is not helping them spread their message.
If you ask to put up a poster on the side of a building, the building owner is allowed to refuse permission. That is not censorship.
Blocking violent groups shouldn't be controversial. I think most of us would block an instance run by ISIS, for example?