We have the exact same line-drawing question in the real world. All kind of infrastructure and different levels over ownership go into a place like a bar, but t

We have the exact same line-drawing question in the real world. All kind of infrastructure and different levels over ownership go into a place like a bar, but that doesn't mean the bar owner isn't responsible. There is a similarly clear difference between an ISP (how the customer gets to the bar), a web host (the landlord, maybe), and the website itself (the bar). On the other hand, investigating whether someone committed a crime is a little bit different online vs in the real world. Part of what websites could do is make it easier to run those investigations by making reporting easier- Twitter reporting, for example, is relatively hostile to people trying to report bad behavior.