Laws and regulations against censorship technically only apply to government agencies.

The great twitter blocking debacle for instance actually came down to the interpretation of blocking as telling someone to “shut up.”

Ordinary people, and non government bodies may tell anyone they want to shut up. These entities may even sanction or remove communications in so far as these relate to their platform or properties (as long as not destroying evidence of a crime.)

Governing bodies however may not, excepting those circumstances which constitute harassment or other disorderly conduct.

To elaborate a bit more on your comment regarding “hackers”, while these may well be hypocritical, one must be wary of stereotyping. Are these same persons advocating free speech the exact same ones interfering?

Not everyone has to listen, though no one has the right to harass others.

Definitions don't matter. The definition is whatever the dictionary says it is. Which is, in turn, the lexicographer's best understanding of how people used the word at the time. None of it has any bearing on what you really want to know.

What you really want to know is that there is a longstanding tension between speech as pure, value-neutral information with no physical effects, and the large number of cases where speech does have a real-world effect. These conflicts aren't easily resolved, and aren't helped by simplistic, absolutist approaches.

Don't expect any solution to be uncontroversial. Don't expect any solution to make you happy. Starting from there, we can ask: what is a state that we can all live with, that offers the maximum freedom to every person -- with the understanding that it won't be absolute freedom for the same reason that your right to swing your fist ends where my nose begins. And despite words not being the same as a punch in the nose, they do have real-world effects.

> What Is the Definition of Censorship?

This should be answered by a dictionary or an organisation with specific knowledge of its history. Perhaps consult Wikipedia¹ and the ACLU².

> Take HN for example. I would have thought hackers

HN is not a uniform blob of people. Neither are “hackers”. Nor is the former frequented only by the latter.

> would be free-speech oriented

As XKCD reminds us³, “free speech” does not mean people have an obligation to listen to you. If you go into a building and begin spouting insults at everyone inside, it’s not censorship if people ask you to shut up and leave.

> in a group, they are just as good at punishing differences as high-school bullies.

You seem to have a point you want to make. If that’s the case, please make it directly and honestly. Indirect jabs⁴ are more likely to get you downvoted than the content of your ideas. HN optimises for curious, kind conversation. Snakiness is explicitly frowned upon⁵.

¹ https://en.wikipedia.org/wiki/Censorship

² https://www.aclu.org/other/what-censorship

³ https://xkcd.com/1357/

⁴ https://news.ycombinator.com/item?id=36197063

⁵ https://news.ycombinator.com/newsguidelines.html