Of course it is accurate, it is just that it is of little use to use in determining whether two users are the same. you need the entire IP address to know that. I see it as a deterent to multi nic users in that they are now aware that HC can identify them and ban them - look at christopherskase=miltonbrown this morning!!!
Don't forget that there are 65,536 possible IP addresses that start with 211.27 - so concluding anything about them is like saying that because my mobile phone is 0410 xxx xxx then I must be the same as every other person whose phone number starts with 0410.
