As far as I am concerned, "hate speech" is a sort of unmoral expression which might be harmful to others. "Hate speech" usually shows sensitive topics such as genders, religion, race and so on.
I would definitely support setting limits on free expression. Since it is apparent that hate speeches are harmful, we need to prevent free expression to those unmoral expression. I would like to define those limits as a kind of rules that can protect most people and do not show any bias. For instance, speeches that insult people who are homosexual should be considered as an hate speech.
From my point of view, reaching an international consensus on defining hate speech is not a wise choice to solve the problem. People from different parts of world have various understandings and views toward certain things. Thus, we cannot use the same scale to measure hate speech among different cultures.
I think censorship and filtering of hate group websites are necessary, especially for political purpose. For instance, a few so-called "religions" in China put articles and posters that showed they attempted to fight against the government on their website. In this case, if the government still did not take any control of it, it would be definitely a disaster.
Lierally, it seems like hate-oriented Web sites creators are not responsible for crimes of others, especially their readers. In fact, as I mentioned above, sometimes, if the government ignores those Web pages, the society is the one most likely will take the price of it. Additionally, it probably will lead to a disorder in the society.
As far as I am concerned, special restriction should be sat in order to protect children using the Internet. I would suggest that people should be required to show their ID when viewing those Webs. By doing so, whether the one is adult or child can be soon identified.
This problem has some similarity with the question that should there be any distinction between oral and written crime. From my point of view, such distinction should not be made in order to build a relatively stable society.
I think there is no difference between hate-related material and objectionable material, since both of them are unstable elements to the society from my perspective. Therefor, both of them should be strictly monitored by the government.