Yeah, true in principle. But that can turn into a never ending chase too, as people hide the URL in hard-coded-IP expressed in various forms, etc.
BTW, do you know of a HTML filter for the client side? From time to time I've attempted a bozo filter for FR (no, you aren't a bozo), but can't find anything.
Yes, sort of. You can use your HOSTS file to direct particular domain names to a null IP (127.0.0.1). For example if you put:
127.0.0.1 rotten.com
into your host files you computer will never access anything from rotten.com.
The HOSTS file can also be very useful for blocking popups and many types of ads.
For more information about HOSTS, Google "HOSTS file"