The problem for you is that you can't do much against it. The domain owner can easily change the record, you can't. The only way is to blackhole all requests co

The problem for you is that you can't do much against it. The domain owner can easily change the record, you can't. The only way is to blackhole all requests coming in for domains other than the ones you want to host. Or is there any way to get the DNS records checked?