Replying to the updated FAQ in this post:

> Since GDPR back in 2018, I've found that data to be mostly useless. What you get is either nothing, a registrar web form, or a relay address

This is the way though. If there is no contact in the domain's whois, then contact the abuse handler for the IP address that it's hosted on

Domain registries (not the registrars) are usually very interested in dead contact methods, at least I've been repeatedly threatened with losing the domain if they find it's not functional. You usually get like two weeks to fix it if issues are found, but they do seem to care. Maybe not .ru (I have no experience with them), but in general I'd let them know and see if that triggers an update before moving to more drastic measures

Another way would be looking for an email address on the homepage or pages linked from the homepage (usually /contact or /impressum or such, but of course this varies)

Lastly, some people may be willing to help out and look for a contact method in a crowdsourced manner. Could also use an LLM but I expect people are more reliable and volunteers are cheaper too

> If the list is widely disseminated and absorbed into blocklists, trying to get your domain of those lists afterwards is close to impossible. For a small business, that could be devastating.

As someone who experienced this (thankfully just a hobby project and not a business), thanks for that consideration! However, I'd encourage this line of action for the ones that are uncontactable. If the site is abandoned, what else are you going to do?