Smartphone dystopia - proof that the smartphone is your enemy Mark noticed something amiss with his toddler. His son's penis looked swollen and was hurting him. Mark, a stay-at-home dad in San Francisco, grabbed his Android smartphone and took photos to document the problem so he could track its progression (https://nyti.ms/3PGqC65). It was a Friday night in February 2021. His wife called an advice nurse at their health care provider to schedule an emergency consultation for the next morning, by video because it was a Saturday and there was a pandemic going on. The nurse said to send photos so the doctor could review them in advance. Mark's wife grabbed her husband's phone and texted a few high-quality close-ups of their son's groin area to her iPhone so she could upload them to the health care provider's messaging system. In one, Mark's hand was visible, helping to better display the swelling. Mark and his wife gave no thought to the tech giants that made this quick capture and exchange of digital data possible, or what those giants might think of the images. With help from the photos, the doctor diagnosed the issue and prescribed antibiotics, which quickly cleared it up. But the episode left Mark with a much larger problem, one that would cost him more than a decade of contacts, emails and photos, and make him the target of a police investigation. Mark, who asked to be identified only by his first name for fear of potential reputational harm, had been caught in an algorithmic net designed to snare people exchanging child sexual abuse material (https://nyti.ms/2nBmH3a). Because technology companies routinely capture so much data, they have been pressured to act as sentinels, examining what passes through their servers to detect and prevent criminal behavior. Child advocates say the companies' cooperation is essential to combat the rampant online spread of sexual abuse imagery. But it can entail peering into private archives, such as digital photo albums - an intrusion users may not expect - that has cast innocent behavior in a sinister light in at least two cases The Times has unearthed. Jon Callas, a technologist at the Electronic Frontier Foundation, a digital civil liberties organization, called the cases canaries " in this particular coal mine." "There could be tens, hundreds, thousands more of these," he said. Given the toxic nature of the accusations, Mr. Callas speculated that most people wrongfully flagged would not publicize what had happened. "I knew that these companies were watching and that privacy is not what we would hope it to be," Mark said. "But I haven't done anything wrong." The police agreed. Google did not.