A GIF that triggered a US journalist’s seizure should be considered a deadly weapon, a Texas grand jury has said in an unprecedented ruling.

Magazine reporter Kurt Eichenwald, who has epilepsy, was sent a strobe-animated GIF by an anonymous Twitter user in December last year.

It said: “You deserve a seizure for your posts.”

Eichenwald’s partner replied to the message: “This is his wife, you caused a seizure. I have your information and have called the police to report the assault.”