They enforce this by IP on other chess servers.
Highly doubtful. Most people when you restart your computer, you get a new IP. It is well known, for websites, that IP blocking is quite useless.
That's just simply not accurate. I don't really care enough to go into great detail as I woke up this morning to study chess but the simple refreshing of a few digits in your IP is not enough to circumvent the IP detection methods several websites have in place here in 2015.
They enforce this by IP on other chess servers.
Highly doubtful. Most people when you restart your computer, you get a new IP. It is well known, for websites, that IP blocking is quite useless.