At first the ISPs were blocking the sites by their IP addresses. But it is easy to change the IP address, so now they are required to constantly follow the chan

At first the ISPs were blocking the sites by their IP addresses. But it is easy to change the IP address, so now they are required to constantly follow the changes of A records of the blocked domain and block all the new IP addresses as well. This is where the exploit comes. If your site is blocked you can add kremlin.ru's IP address to your domain's A records and the kremlin.ru will be automatically blocked.