The recent proliferation of believable deepfake videos - including ones featuring actor Tom Cruise - have raised new fears about phony events that can be used to sway public opinion. Hany Farid, a professor at the University of California, Berkeley, says that the Cruise videos demonstrate a step up in the technology's evolving sophistication. "This is clearly a new category of deepfake that we have not seen before," said Farid, who researches digital forensics and misinformation. Deepfakes have been around for years, but, Farid says, the technology has been steadily advancing. "Every three to four months a video hits Tik Tok, YouTube, whatever, and it's just — wow, this is much, much better than before," he said. Another story on this topic appeared on ABC News.