alika - 7:09 pm on Jul 26, 2010 (gmt 0)
In our case, we've had several instances where our whole site, including Adsense code, were copied. Hence, we very much welcome this feature and has been using it.
Luckily for us, I suppose, we don't have a lot of sites so a 100 limit is not a problem
It all depends on what risks you think your site faces. But if you've experienced being copied or someone duplicated your site, this is a must-use feature