“One can easily imagine the terror, the fear and the horror that gripped the airplane passengers who were forced to make an emergency landing, some of whom were injured while evacuating the plane,” the judge, Zvi Gurfinkel, wrote in his verdict, “and the terrified panic caused when there was a need to evacuate pupils from schools because of fake bomb threats.”

A United States indictment has also been served against the hoaxer, who holds both Israeli and American citizenship, as the Justice Department has accused him of hate crimes.

The teenager from southern Israel was legally a legal minor when he began his campaign of terror. He was convicted of the crimes committed after he turned 18, including extortion, making threats and false reports, conspiracy to commit a crime, and money laundering.

Using sophisticated software to camouflage his voice and disguise his location, he offered his services to others on the dark net and traded in drugs, bomb-making guides and child pornography — all from his bedroom in the fifth-floor apartment in the southern Israeli coastal city of Ashkelon, where he lived with his parents, officials said.

After months of an investigation by the cyberunit of the Israeli police, in cooperation with the Federal Bureau of Investigation and other foreign police and security agencies, the apartment, in an upscale neighborhood, was raided in March 2017, and officers arrested the teenager.