Currently you can anonymize the websites you create. People doing a search are blocked from finding out who you are. But you’re not anonymous to the registrar. And now the registrar could be a Muslim fanatic persuing who owns “stopmuslimimmigration(dot)com” or whatever name you use.
That is exceedingly dangerous.
This scenario is known as taking somebody off the air.
While ICANN has that technical capability now everyone supposes it won't be used in a nefarious fashion because they have not done it to registered web sites.
But, if it happens twice the US and every other country will start their own registration service and root domain.
ICANN would be relegated to resolving national domains...like dot cn. or dot US.
The ability to discover the actual owner/publisher of a web site.
The person or entity.
Yes, ICANN knows. And yes, if a bad guy gets access to those records they would know who to go after, personally.