I personally believe that there is a difference between what is right (in the legal sense), and what is practical, and a difference between what is right and what makes good business ethics and practice. These are things that often should be left up to an individual to decide (where they do have the choice, that is), so my primary goal for continuing to discuss this topic is purely to determine an irrefutable, factual answer to the question 'who is legally responsible...", and I should note that is a little different to "who can, at least initially, be made responsible by eBay / PayPal / credit card providers?"