Thank you for clarifying the OP's intention. It indeed makes sense to advise the domain registrants to be careful about cleaning up stale DNS entries. Yes, if

Thank you for clarifying the OP's intention. It indeed makes sense to advise the domain registrants to be careful about cleaning up stale DNS entries. Yes, if a domain points to IP addresses of servers we do not control, many bad things can happen. Here is a really interesting security disclosure related to stale DNS entries that comes to my mind: https://thehackernews.com/2019/04/subdomain-microsoft-azure.html https://thehackernews.com/2019/04/subdomain-microsoft-azure.... .