OK, if the court can determine whether a consumer has a degree of responsibility, surely a consumer can determine if she's participating in a "copyright infring

OK, if the court can determine whether a consumer has a degree of responsibility, surely a consumer can determine if she's participating in a "copyright infringement"? If you search the Web for "watch big buck bunny online free" and download/watch one of the found files, can you tell when you infringe copyright and when not?