Regarding child protection laws:
* COPPA should be enabled by default
* When staff are emailed, they are informed to reply with the ToS, the moderation tools used, and general confirmation that this agreement happened.
* Add template support to the email module including a default template for "COPPA" confirmation. Generate it by PHP which includes current rules and the current content moderation tools (every addon that might possibly censor or moderate content / users needs to self-report through another set of hooks similar to privacy).
* Document how all of this is going to work; some users' parents may need to be replied to offline (just copy the generated text from the email module to a word processor).

We will also need to add an action log for when a specific email template was used, so we can audit that audit information was sent to the parent of a kid :D. Scientologists would be proud of this level of auditing.
We will need to document this, and also document it that if doing it offline, you should also keep your own records.

The saving of declarations and prompting for re-agreement has been implemented as of 11.alpha3

I decided against treating the edge case as a hack attack. I can see where that will cause issues. Instead, a user error will be thrown if the submitted declarations do not match what was configured.

I plan to also implement simple emails of the declarations for v11.0 to ensure legal compliance. E-mail template functionality, which is not necessary for legal compliance but will improve the UI, will probably be a later version.

Very basic support for sending e-mails with templates added in #5784 . Currently resides in the tickets module as it is designed to be used with guest support tickets / e-mail integration. Consider refining the code and then moving it to the email module with tickets support if the addon is installed.

Automated response: Add rules confirmation e-mail

This commit adds support for automatic e-mails of the rules / declarations agreed to both when a member registers and when a member re-agrees to changes. It includes a full copy of the rules page and the Privacy Policy page.

Issue will remain open as other parts of it have yet to be implemented.

Not sure what else was left to implement; I think this is complete.