Why not try to warn the owners first? Taking the site off of those lists is a pain.

How do you do that if the website has no contact details and WHOIS contact form gets no reaction?

	▲	Aachen 7 hours ago \| parent [-]
		Contacting the registered abuse contact (per the WHOIS data) is just step one. If that fails then, sure, go ahead and let the domain registry know that the contact method on their file is dead and then it makes sense to put the sites on a blocklist