Prime Minister Jacinda Ardern says there must be globally-coordinated action to clamp down on social media.
The PM is right. Companies such as Facebook and YouTube owner Google are multinationals, and co-operative action is needed to effectively regulate them.
As things stand, jurisdiction is in dispute amid a game of cat and mouse.
Privacy Commissioner John Edwards - who asked Facebook to give NZ Police the names of its users who had shared the banned Christchurch video - said, "I remain of the view... that Facebook is subject to New Zealand law in relation to the collection, use, storage, access and disclosure of personal information".
Facebook - which refused Edwards' request - had terms of service until May 25 last year that put its New Zealand users under Irish privacy law - Ireland being where Kiwis were billed for Facebook ad services, at the time.
But on that date, as tough new EU privacy regulations came into force, the social network changed its terms of service to place its New Zealand users under lighter US privacy law.
A global clampdown, if it can ever be achieved, will take time.
In the meantime, various countries are trying unilateral action. Bloomberg reports the social network has hired fact-checkers in the run-up to India's May 19 election, although just 11 staff face grappling with the deluge of "fake news" swamping 900 million eligible voters in the world's largest democracy.
In the wake of the weekend's terror attacks, Sri Lanka blocked social media sites, saying misinformation and hate speech on Facebook, Instagram and other platforms could sow confusion and incite more violence.
But less extreme action can yield results. At the start of last year, Germany introduced a law to effectively class social networks as publishers (Facebook and its peers describe themselves as content-neutral platforms) - and introduced fines of up to 50 million Euros for any failure to remove "manifestly unlawful" offensive content within 24 hours.
Facebook dedicated 65 staff to enforcing the new law and, in short order, they were deleting hundreds of posts.
Concern has now switched to fears that the law, known as the Network Enforcement Act, is too successful and risks crimping free speech.
Similarly, alarm bells were sounded in the first week of April, when Australia's Parliament responded to the Christchurch attacks by passing tough new social media measures, threatening social media companies with fines up to 10 per cent of their revenue and their executives up to three years' jail if they fail to remove "abhorrent violent material expeditiously".
NZ Council for Civil Liberties chairman Thomas Beagle said the Australian measures were poorly thought through, rushed and impractical. And it's likely any attempt to enforce them would be problematic.
And yet, the law change across the Tasman coincided with an assertive new stance from Facebook Australia-New Zealand, which had initially dragged its heels after March 15 but began moving against various hate groups.
Australian PM Scott Morrison has already put a social media crackdown on the agenda for the next G20 meeting in June in Tokyo. That will likely be the start of a long bid, including efforts by Ardern, to reach a consensus. While we wait, there's already evidence that local law changes can help focus Facebook's attention.