It's like trying to hold an electricity company responsible for someones counterfeiting machine. Or a phone company responible for the mob communicating a hit order.
A taxi driver doesn't have to do active investigation to notice a user doing something wrong.
Playing the devil's advocate
The argument is what if I lived in a remote area and the only way for me to work is to use the Internet. In addition to work, I pirate MP3 files using the Internet. Does the ISP have a responsibility to stop me by cutting off my service? By doing that, there's no way for me to work, and thus my livelihood is jeopardized. Furthermore, is the ISP really allowed to judge that what I am doing is something illegal and convict and punsih me, thereby denying me the right to make a living?
But what if I lived in a remote area and the only way for me to get into town is to use a taxi service. On my way into work, I roll down the window and start shooting at people. Does the taxi driver have a responsibility to stop and tell me to walk out? By doing that, there's no way for me to get to work, and thus my livelihood is jeopardized. Furthermore, is the driver really allowed to judge that what I am doing is something illegal and convict and punish me, thereby denying me a right to make a living?
I'm not a lawyer, but could the ISP or the taxi driver be liable for reckless or criminal indifference if they didn't stop me?

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