When you USE the (illegally copied) software you receive, you are making a copy and/or derivative work in violation of 17 USC. (By copying into the computer memory). Since you are not legally entitled to the copy, the safe harbor provision of 17 USC 107 does not apply.
Right you are but since there can no be reason as to why anyone would have a right to scan my computer, due to my right to privacy, no one could know that I had the illegal copy. So how could anyone prosecute me for having a copy of it, unless I commit some other crime that entitled a search of my property? Or am I missing something? So it all boils back down as to why I should respect intellectual property. I need an argument.