I don't know of any country where "racism" as it would be expressed on an online forum is illegal...

Acting racist by denying someone their rights or physically harming them is illegal because those are crimes... saying you hate one race or another is not.
That said though it's not illegal most legitimate hosting companies have a terms of service which disallow racist, hateful, or pornographic material to be hosted with them. If there's any child porn that is a serious crime and you should call the FBI (if you are in the USA).