I'm not sure why YouTube should be able to operate the service it does with the little content filtering it does. In what other industry would you be allowed to post child pornography because it's too difficult to make sure it doesn't get posted? No newspaper could take that excuse. Toys R Us couldn't say "oh jeez, we didn't realize that a corner of our store was being used by child pornographers to spread child pornography and also recruit children" and not be liable. I'm not sure why we think it's good to give an excuse to YouTube and Facebook for this and anything else anyone else would normally be liable for.