Great metaphor I heard yesterday about 230 - think of three things: paper, the newspaper stand, and the newspaper publisher.
Obviously the company that makes blank paper newspaper publisher's buy is never liable for what's printed on it. They sell it blank!
The newspaper publisher is of course liable if they decide to make a new paper called "How to build Bombs Weekly".
And even the newspaper stand is liable if they decide to carry this new paper. (They are not liable for something bad printed in a mainstream paper since they had no way to know a normally good publication would suddenly include something terrible.)
Now what is youtube? Do they make paper, or are they the newspaper stand?
