More specifically and related to krapp's comment, the system is already in place via section 230 at least for the USA. It is on the website operators to remove illegal content in a timely manor rather than find a fullproof way to prevent it in the first place.
In the practical sense the implementation of this varies by hosting platform, where the site operators reside, how popular the platform is and how much attention it garners political, social, etc... and how diverse an audience the platform has. Small sites can lose their hosting accounts, CDN accounts and DNS registration if they do not remove content in a timely manor. Small VPS providers will nuke an account without hesitation because they stand to lose more than they gain from the tiny bit of money they make from having the account holder.
Bigger sites, especially those operated by big corporations are expected to put more mitigating controls and audit trails in place. Big corporations buy themselves some leniency by creating portals for law enforcement to get audit trail data real time without requiring warrants.
I am not a lawyer and this is not legal advice.
Still suspect you'd have someone using the law as a tool to remove the platform the first time they had an issue with one of your users. "someone said something bad there once, nuke it from orbit" has a longer tradition than the concept of nukes... or orbits.
https://anarchonomicon.substack.com/p/cocytarchy
As the internet more closely resembles the prison the users grow more responsible. Just surveil everyone.