I had this idea to make a network where people can get paid to let other people use their computer for computing purposes. Let's say they got permission to use Person B's computer under terms and conditions, basically saying:
"I will not do anything illegal using this computer."
And they agreed upon the terms. But Person A used Person B's computer to do something illegal like, let's say, distributing paid music for free (without permission) using that computer as a server, so they are violating copyright law. But how can one say "Person B is innocent!" in a valid way, before they have to even leave for court.
Oh, and Person A and Person B both have unlimited liability.