A 75,000-member Facebook group has been disbanded after a complaint about posts, comments and admins' moderation of the site.
Facebook figures show such groups sprung up and took off exponentially in New Zealand during lockdown, but the burden of policing them often falls on a handful of people.
When the subject matter is controversial, or is regulated by government officials, they can fall foul of the law.
Advocates say Migrants NZ was a popular site - with hundreds of posts a day from migrants, who felt isolated and ignored by official channels during a time of policy flux and visa delays.
They say a complaint to the Immigration Advisers Authority (IAA) was from disgruntled professional advisers who wanted to silence a forum offering free information.
One member said the group, which included about 200 immigration advisers and lawyers among its members, was started so that information on skilled migrant visa delays could be shared but had grown into a thriving network for new arrivals.
"It was just a mental support really to talk with like-minded people," she said. "I personally think if I know what's going on I can deal with it a lot better, instead of being in the unknown. And the group was that medium that people got good information from, instead of being on hold with Immigration for two hours at a time to get a response that doesn't tell them anything really."
Immigration lawyer Alastair McClymont said when the group closed down last month, there were clear factions among advisers who backed the social media forum and those glad to see it go.
"Shortly before this IAA complaint, there were advisers complaining on the group that information that had been given to advisers or to advisory groups should not be shared with the general public because somehow that was some private property that belonged to immigration advisers."
If incorrect advice was given on the site, a professional adviser or lawyer would jump in to correct the record, McClymont said. "So I really don't think that there's any risk at all of any members of that group acting upon advice that they were receiving in the Facebook group."
Group administrators received a lawyer's letter in January, warning the site had defamed an immigration adviser who spoke out against members giving advice on the site.
Later, a group of advisers approached the IAA asking it to investigate whether unlicensed advice was being provided on the site.
In March administrators received a letter from the IAA, which said they could be in breach of the law and it may take enforcement action if it "receives new evidence of offending, or a lack of appropriate measures to moderate the group and comply with the act".
With so many posts and comments, the admins did not think it was sustainable to moderate each one, and the group was disbanded last month.
The IAA has this year provided resources for professionals to share when they see potentially unlicensed advice being provided, and is advertising on social media to direct migrants to its register of licensed advisers.
IAA principal Investigator Simon van Weeghel said anyone using their knowledge or experience and immigration to advise, direct or assist someone with immigration matters could be in breach. But there were exemptions, so it only gave a warning to Migrants NZ.
"There are exemptions from people being licensed and one of those is where the advice is given to them in an informal or family context only - as long as the advice isn't provided systematically or for a fee. So that's one of the exemptions that we took into consideration when we were having a look at the complaint.
"The majority of the information we were given, most of it seems to be one-off opinions from people and things like that. So it looks like it fell under the exemption for informal contexts and would therefore be exempt from having to be licensed."
Authorities relied on members of private Facebook sites to bring problematic posts to their attention, he added.
One of the advisers who approached the IAA, Sukhpreet Kaur, said they had raised concerns with admins of the group in the past and were not opposed to free advice being offered.
"There were several advisers who sought clarification from IAA about the unlicensed advice being encouraged, facilitated and provided in the group. From what I understand, IAA did not ask admins to close the group. IAA reminded the admins about their responsibilities as group admins to not approve posts which will lead to unlicensed immigration advice.
"If the admins have decided to archive the group, it is their decision. Our responsibility is to raise our concerns to the relevant authority. IAA is a government body to regulate the provision of immigration advice. Any steps it takes towards protecting migrants can only be good for the migrant community."