[1]: https://medium.com/@monteiro/this-article-first-appeared-in-...
Using a person to purchase firearms for a person who can't get them is called a straw purchase.
Maybe advertising something other than a gun to sell a gun should be covered under straw purchase.
They shut down the NZ Hunting Facebook group, which had over 10,000 members because people were selling firearms on it (which is not in violation of New Zealand law).
Working towards requiring registration/background checks of private sales would actually accomplish what they want. Lobbying Facebook to disassociate themselves from the sales will accomplish little more than moving the sales off of Facebook.
And of course, given that there are tens of millions of unregistered firearms in the US, all a registration law would do is inconvenience people willing to comply with it, it wouldn't stop people looking to get a gun without registering it.
There is no reason a buyer shouldn't be able to go to the ATF website submit themselves for a BC and get an approval code for a seller to verify. That respects privacy and gets you closer to 100% background checks. No responsible gun owner wants to sell to a felon. Thats why a lot will only do private transactions with CCW permit holders.