I see the NZ government actions in a different light. The media clamp down as far as I'm aware has been all about suppressing the video the killer live streamed as he murdered over 50 people.
I don't know want the laws are in other countries but in the U.K. - You are not allowed to show people dying on television. That may seem barmy when films and tv shows seem to revolve around violence and death.
For a broadcaster you are not legally allowed to show a real death.
Live streaming has changed all that. Now anyone with a webcam can broadcast what they like. That's only really happened in the last few years. Jihadis showing beheadings - content that is offensive and downright evil, and other footage like the video of the Christchurch killer can be spread without any problem at all.
So kinda of counter to what we might think we have a new type of media, social media which is almost completely unrestricted. Facebook and google make billions but we all know are staffed by a handful of people. There are not enough staff protecting the users. Letting this type of footage go viral normalises it.
The Uk changed the advertising regulations for gambling, about ten years ago, after intense pressure and lobbying from the gambling industry claiming that U.K. firms couldn't compete with online competitors from overseas. Gambling ads are on the Tv all the time now and the result - a complete normalisation of gambling among the young. The figures released about the number of school children gambling in the U.K. is now collosal.
There is definitely a balance to be struck between freedom of speech and some kind of protection of its abuse by negative influences