The arrest of a Salisbury, Maryland, man accused of giving a well-known journalist a seizure by sending him a flashing image online represents a new kind of prosecution for a new kind of crime.
The journalist, Newsweek's Kurt Eichenwald, suffered a seizure in Dallas after viewing the flashing animation when he received it via Twitter late last year, according to a statement from the Justice Department.
Eichenwald had written about his epilepsy and publicly described a similar attack several weeks before the Dec. 15 incident, and authorities said the alleged attacker sent Eichenwald the image in an attempt to hurt him as revenge for what he saw as the reporter's critical coverage of President Donald Trump.
Experts on cybersecurity said the incident was not the first in which technology was used to expose medically vulnerable people to injury, but some said it was the first time they've heard of prosecutors bringing criminal charges in such a case.
"This is a new era," said Kevin Fu, a computer scientist at the University of Michigan.
Authorities took John Rayne Rivello into custody Friday on suspicion of sending Eichenwald the image along with the message: "You deserve a seizure for your post." Rivello has no previous criminal history, according to public records.
Legal experts compared the alleged crime to sending a letter bomb in the mail, or to purposely giving a person a dangerous allergic reaction.
"What is new, because of the technology, is the ease with which certain individuals can be targeted across state lines by remotely distant perpetrators," said Andrea Matwyshyn, a law professor at Northeastern University.
In 2008, hackers introduced seizure-inducing images onto the website of the Epilepsy Foundation, an organization that provides resources for people with the condition. The group quickly moved to address the vulnerability, and although several users reported headaches and conditions that can be precursors to seizures, none were reported.
Although epilepsy is relatively common - about 4 percent of Americans have some form of the condition - very few have seizures triggered by flashing lights.
"If you were going to target a particular person with epilepsy, you would have to know that this particular person was light sensitive, and that would be very rare," said Jacqueline French, the Epilepsy Foundation's chief scientific officer and a professor at New York University.
Eichenwald declined to comment Saturday and referred questions to his lawyer, who did not respond to a request for comment.
In his essay describing the first incident last fall, he said he received a video that contained a strobe light, with flashing circles and images of Pepe the Frog - often used as an alt-right meme online - flying toward the screen. In that case, he avoided a seizure by dropping his iPad. The similar message on Dec. 15 triggered convulsions.
Rivello, 29, apparently knew that Eichenwald would be sensitive to the images, authorities said. His father, David Rivello, declined to comment Saturday about his son's arrest when reached by telephone. Several other relatives did not respond to requests for comment.
Neighbors in Salisbury, on Maryland's Eastern Shore, said Rivello lives alone in the house that he grew up in, usually seen only when he was out mowing the lawn or arriving home in a pickup truck that appeared to have a bad muffler.
Rivello told one of his neighbors that he worked as a financial markets day trader. He appeared to live modestly.
"I've only talked to him a couple of times," said Phillip Kemmerlin, who lives next door. "I've never really seen him walking in or out with anybody. I didn't know he was a political type of guy."
Online, Rivello has been exuberant about his hard-right politics, often tweeting dozens of times per day about his support for Trump and his frustration with anyone out of step with the White House agenda.
His latest Twitter handle - "Meme Magic Mike" - features photos of a scowling Trump in sunglasses and a leather biker's jacket and describes Rivello as a "drinker of leftist tears. Snowflake melter."
Between sneering jabs at cable television host Rachel Maddow or U.S. Sen. Charles E. Schumer (D-N.Y.), Rivello repeatedly highlights what he characterizes as a feud with Eichenwald and dismisses any pain the Newsweek reporter has experienced.
"This reminds me of a boy who cried wolf over a Pepe cartoon," he wrote on March 10 in response to a tweet by Eichenwald about a white woman at an airport complaining about being racially profiled at the security checkpoint.
"He accused me of 'attempted murder' by deadly Pepe meme back in October," he wrote about Eichenwald.
The taunts inspired some of Rivello's 3,365 followers to post similar strobe images to Eichenwald's Twitter handle.
"Dammit Goldstein, ur bitin' my style!" Rivello typed in reply to a December post featuring a sad face framed by furiously blinking lights.
Although the Constitution offers broad protections to critical speech in public forums, experts said it is unlikely Rivello could successfully defend his actions as protected expression.
"This doesn't even get in the door of the First Amendment," said Danielle Citron, a legal scholar at the University of Maryland. "It doesn't have expressive value. . . . It doesn't express someone's autonomy of views and opinions. It's not contributing to the marketplace of ideas."
Citron said there are other types of medical cyberattacks that could prove harmful to others and be considered crimes, such as the possibility that someone could hack into and take over a pacemaker or an insulin pump and kill a patient. Johnson & Johnson warned patients last year that the company had identified a vulnerability in one of its insulin pumps, a device used by about 114,000 patients, Reuters reported.
"This problem isn't a one-off with Kurt Eichenwald," Citron said. "It's of a piece with all sorts of other phenomena."
Hospitals are also at risk. In 2015, federal regulators warned that a drug pump manufactured by the medical-device company Hospira could be hacked, with potentially deadly consequences.
Fu, of the University of Michigan, said that a more common problem is malicious computer code, circulating online or on portable drives, that can end up in hospitals' systems. A hacker might not be specifically targeting the hospital, but the code could cause the medical hardware to malfunction all the same.
"It's about knowing what's at risk," Fu said. "You can't protect what you don't know you have."
• 07/25/16: Why Clinton's pick for VP might contradict her message on Wall Street
• 05/02/16: How Hillary's positions have changed while running against Sanders
• 03/08/16: Even Bernie Sanders can beat Donald Trump, according to math
• 03/07/16: The key difference between how Trump and Romney made their money
• 02/15/16: What happens when a Supreme Court justice dies in an election year?
• 12/07/15: Why you should stop calling Donald Trump a fascist
• 12/04/15: Contrary to conventional wisdom, the U.S. has actually had a major decline in gun violence. But here's why