Politcians as well as Lawyers use language as weapons and not by means of communication. In the context of this particular subject, by invoking the name of “terrorism” there are particular parameters of which the social narrative assumes we comply with in the public sphere. “Murder” has different parameters normally associated with a domestic dispute and sometimes can even be interpreted as justified such as a “crime of passion”. On the other hand if the society has been conditioned and subdued to believe that Terrorist are pure evil and cannot be prevented and subdued by the normal means of domestic law and enforcement, then the scenario of “crisis, problem, solution” is conveniently sold to the public to engage in this regime change foreign wars for profit. Politicians are not grievance counselors, they are ambulance chasers. They take advantage of our vulnerable emotional states at critical moments to mobilize policy and law changes that we normally might not agree with. This is why labels, terms, and interpretations are so powerful. That is why one side can label someone as Racist and shut down the conversation, or the other calling them Communist. The critical thinking mind will be the most powerful tool of this decade, cutting through the BS name calling and demeaning rhetoric from both sides. Politely making one arguments in a way that the otherside is willing to listen and at least consider will be the only way through this Dualistic jockular mud slinging contest. We will always have at least 2 sides of a situation but we need to return to a civil and respectful exchange of ideas. Otherwise some type of civil unrest will have to exhaust the pent up anger and grudgeon energy until we come back together to rebuild civil society.

I live in New Zealand and have done all my life. I'm in Auckland now, but lived in Christchurch from 2000 to 2007, about ten minutes from the Linwood mosque. It's a very polyglot area (I used to joke that I could hear ten different languages on the way to the store across the road). Personally, I loved that aspect of life in Christchurch. East Linwood is one of the most 'diverse' (for want of a better adjective) and also one of the most dangerous parts of not only Christchurch but of the South Island in general. It should be said that - at least when I was there - this was far more due to unemployment, low wages and drug/drink abuse than anything else. Racial pejoratives were shot back and forth when people were fighting but the fights seldom came from ethnic or cultural differences.

I'm nearly finished reading Brenton Tarrant's, 'manifesto'. He is more a white separatist than a supremacist, claiming that the country most in line with his views is communist China (although he is not a communist). This is really just identity politics, taken to its logical conclusion, a point that will be either completely missed or deliberately obfuscated by our (and no doubt, your media). He claims that he has no problems with Muslims in "their lands" but not in "white" countries. The manifesto is 73 pages long (there are graphs, lists and headings, so it doesn't seem that long) and for those genuinely interested in what has happened here, it is worth reading.

With due respect to James Thompson (OP), I do not think this man is insane, his horrific and deranged actions notwithstanding. His writing is not particularly good and his grasp of logical argument leaves a lot to be desired (as does his highly selective knowledge of history) but it is not the rantings of a lunatic. He expresses great admiration for Oswald Mosley but doesn't really fit into any of the major political shoeboxes easily.

What is abundantly clear is that his actions (we're still waiting to hear about the others involved?) are absolutely and specifically intended to start a war, not just here in li'l ole Enzed, but between Muslims, visible minority immigrants and native (white) populations in European countries and countries that were/are colonies of European powers: Britain, USA, Canada, Australia etc.

For those who might not be aware, New Zealand has never before suffered a terrorist attack. In 1985, agents of the French government exploded a device aboard the Greenpeace flagship, "The Rainbow Warrior", killing (albeit unintentionally) an American member of Greenpeace. That is as close to terrorism as we've ever had here. Now, we get to sit back and watch as our default-left media do exactly what this evil person wanted (he says it specifically, over and over again) which is to bring a war to these peaceful shores using identity politics as both means and end.

In 2017 our proportional representation electoral model allowed for a bunch of politically disparate, glorified pressure groups to cobble together with the Labour Party to defeat the incumbent centre-right National Party that had saved us from the worst of the GFC, boosted and solidified our economy and brought unprecedented prosperity to New Zealand. National won the largest number of seats and more votes overall than any other party (it wasn't close either) but.....the media and chardonnay socialists didn't like them so this travesty was allowed to happen and even applauded but the stupid and greedy.

Our Prime Minister, Jacinda Adern, is a declared socialist and third wave feminist who was made leader of her (Labour) party about five minutes before the election, because literally no one else wanted the job. Her true colours, and that of their coalition member, Green Party will become very clear now. She has already stated that our already very strict gun laws will be changed and I foresee a raft of other repressive measures being introduced in the name of "safety". The left finally have their white boogeyman. They don't have to make it up anymore which is what they've been doing for years.

Also worth noting: there has been a Muslim community in New Zealand for many, many years. Some of the younger ones can be irritating (but only on social media) and I don't like some of the crap they spew about Israel (although that's actually more from the left than the Muslims) but the older Muslims keep the younger ones in line and remind them that this is a good place to be. Kiwis are generally pretty accepting and also very frank: when someone gets too close to the 'line" they're warned off before things get out of hand. One of the advantages of a smaller population, I suppose.

Our laws allow for all sorts of extreme measures to combat terrorism and now that our unelected government has the keys to the pantry, well......pray for us. For all of us. People squabble over politics here. We sometimes snarl or write rude posts on facebook - we don't kill each other over it. Neo-nazis, Antifa, KKK, Isis, et al......it's always been so....far away, that violence (beyond the very occasional smack in the eye) over politics has been almost unthinkable. Not anymore. There will, of course, be retaliatory reprisals, which will be answered and those answered in their turn. EXACTLY what this piece of shit stated again and again, was his whole plan.

God help us. All of us.

[www1.cbn.com]
Why is no one talking about the hundreds of Christians killed in Nigeria?... maybe it’s not sensational enough?

Here in the US we had the mass shooting in Las Vegas. A madman rained down bullets from a high tower. Many asked why this wasn't Terrorism. Obviously, he never stated a political viewpoint or acted as part of a group with continued murderous intent towards an end goal.
In my opinion, since this guy had a manifesto that stated his agenda, and if others may follow his beliefs and actions, then the Categorization as Terrorism should help the authorities to investigate and act accordingly while the public knows there may be more to come.

Why is it getting more "play" than the tragic event of 60,000+ Nigerian Christians (most of whom were women and children) being slaughtered 11 days ago?

With regard specifically to the United States' political arena point of view:

Democrat politicians will rush to assure citizens that the attack isn't terror-related because:

1. They fear a spontaneous uprising of citizens overcome by Islamaphobia, resulting in the lynching of any innocent Muslims who happen to be nearby.
2. By categorizing it as "not terrorism," they can use it as a gun control sound bite.

(hyperbolic, I know ... but I feel I've really nailed the underlying sentiments involved)

Honestly, it wouldn't surprise me if President Trump tweets about it, and tries to tie it to terrorism. I don't think many other Republicans will rush to alledge terroism-related, though a few certainly won't back away from that idea if, in their opinion, there is sufficient evidence to support that claim.

If anybody comes across any statistical data that either supports or contradicts this theory, please link it and tag me. Not opinions, and not anecdotes, but actual aggregate statistics.... I'd love to see some numbers on that.

Firstly, it is to keep everyone's adrenals pumping in a state of fear.
Secondly, it is for future sentencing.
Obviously, that is highly simplified.

Who says we all have to agree with the public officials on what they decided to call said violent act?

Until you understand something, you cannot logically act to prevent it in the future.
Some people are trying to categorize these events, and searching for understanding, so that they can discuss how to respond appropriately.

Others see this, and everything else in the news, as something that confirms their ideology in one way or another, due to conformation bias.