"Art is theft," Picasso once proclaimed, and much of the best and most "original" new art involves an act or two of unequivocal, overt theft.� Paradoxically, the law relating to artistic borrowing has grown more restrictive. "The plagiarism and copyright trials of the twenty-first century are what the obscenity trials were to the twentieth century," Kenneth Goldsmith, has observed. "These are really the issues of our time." Beg,...