Artists have been fighting back on a number of fronts against artificial intelligence companies that they say steal their works to train AI models — including launching class-action lawsuits and speaking out at government hearings. Now, visual artists are taking a more direct approach: They're starting to use tools that contaminate and confuse the AI systems themselves. One such tool, Nightshade, won't help artists combat existing AI models that have already been trained on their creative works. But Ben Zhao, who leads the research team at the University of Chicago that built the soon-to-be-launched digital tool, says it promises to...