With all the file sharing that happens on a daily basis, It would be impossible to regulate. By the time we invent the technology to oversee file sharing, people will figure out how to bypass it. Also, the amount of people that currently file-share would lead to overcrowding prisons more then they already are.
Unfortunately, we live in a world that does not always do the right thing. It would be nice to share files online, but what you send can be received by someone who was not necessarily the chosen receiver of your information. Laws are made to protect, but the web is a place that sometimes even the cops can not protect everyone.