Not all people with epilepsy are photo-sensitive.
In December, Kurt Eichenwald, a Newsweek journalist who has written about living with epilepsy, appeared on the US Fox News show Tucker Carlson Tonight to discuss his claims that the then-President-elect Donald Trump had spent time in a mental institution.
Eichenwald stated that the images had triggered an epileptic seizure, and he hoped to investigate and identify whoever sent it to him. The Justice Department said that after viewing the strobe image, the victim "immediately suffered a seizure".
"It contained images of Pepe the Frog, a cartoon character that has been identified by the Anti-Defamation League as a hate symbol", Eichenwald wrote at the time.
In October, Eichenwald wrote that one of Trump's supporters with the Twitter handle "Mike's Deplorable AF" sent him a tweet that included a seizure-inducing video. "Stop sending them", he pleaded. Eichenwald claims the tweet triggered an epileptic seizure.
Steven Lieberman, Eichenwald's attorney, compared the online attack to someone sending a bomb or anthrax in the mail. 'It triggers a physical effect'.
Rivello was taken into custody in Salisbury on Friday, FBI officials said.
Mr Eichenwald is now urging people to stop sending the risky strobe messages after claiming there have been more than 40 copycat incidents since he went public about the attack on him. The attack was also completed in a relatively simple way.
The unusual case has revealed how apparently innocent online tools can be deployed as weapons capable of physical injury.
Meanwhile, Richard Spencer, a white nationalist who is credited with coining the term "alt-right", called Rivello a "hero of the meme war" and proposed to start a legal fund for the suspect.
With some forms of epilepsy, strobing lights can spark seizures. According to the Epilepsy Foundation in MI, 1 percent of Americans suffer from the disorder. The Epilepsy Foundation estimates that certain visual patterns and flashing lights can trigger seizures in about 3% of people with epilepsy.