The entire purpose of no-ip is so a server can keep the same domain easily while their IP changes (Dynamic DNS). I'm guessing that these servers were either rap

The entire purpose of no-ip is so a server can keep the same domain easily while their IP changes (Dynamic DNS). I'm guessing that these servers were either rapidly changing IP addresses or being brought online/offline quickly and Microsoft wanted to locate them by hijacking no-ip so those servers told Microsoft directly when they were changing IP address. Just a guess.