I won't be taking such drastic measures regarding the signup policy. I'll be going straight to reporting to the authorities. https://www.accce.gov.au/report . With all logs, ips, user agents, usernames & emails.

I do not tolerate child exploitation.

Reddthat is currently a one person show on the admin side of things, that doesn't mean that only I deal with content. All of the wonderful moderators also help out here dealing with reports in their own communities.

These people (the posters) have gone out of their way to cause a ruccus, and I'm sure they are feeding off all these stories. We won't be closing our user signups or moving to an application process unless it becomes completely horrendous with bot attacks.

The application processes can be "gamed". They could create an account and sit on it or even wait 30days and then flood it with csam. There is no way for me to tell if a user has good or bad intentions unless I make people write a paragraph of text, even then it can easily be gamed.
Even lemmyworld has had other troll account issues. Ban a person, they signup again with another random email account and start spamming again. The features for anti-spam are not built into Lemmy like they are with Reddit. It's only been 90days since I bought reddthat.com and less than 60 since we had a huge influx.

What the other server admins have done will not change the fact that out of the 1000 servers with open signups, federation of posts is still an issue and actually won't "save" them from having to deal with it. Sure it won't be because of a user on their instance, it will just be a user from another instance posting content to their instance.

The only way to combat this problem with a 100% success is to federate with known good instances via a whitelist instead of only blocking instances.
Which then breeds silos, with not many ways for any new instance to join the big closed off federated ones. This I'm not a fan of.
It ends up being we are all behest to the lowest common denominator of instance and their "security" for lack of a better word.

In saying all this, I will gladly disable signups if it takes anymore time out of my day than what it is currently taking. My family comes first. (Even writing this post took too long 😅 )