This is why Viacom is working so hard to shut down Star Trek fan sites - if they do not, they take the risk that their copyrights to the Star Trek materials become null and void. They have to at least attempt to prosecute people who violate their copyrights. It does not take much thought to see how this could apply in the Geocities case about which I wrote. Geocities has not enforced their rule against bandwidth theft, so they have by default allowed it. It does not matter what is written - a judge could easily decide, in a class action suit, that the policy was implicitly changed by Geocities by not enforcing it.
Policies are only as good as their enforcement.
If you do not enforce anything it becomes meaningless, both in the physical universe and in the eyes of the law. The law works by precedent - what has been decided or done in the past. To give a nice simple example that anyone can understand, you can write a policy that the sky is purple, but unless someone pumps a whole lot of colored smoke into the air it will remain blue. You have to actually do something to make a policy real. My point in the article is that free hosts like Geocities are free for a reason - their customers are not their users.