Moscow - A Moscow court jailed a Russian hacker for 18 months after he altered an electronic advertising billboard so that it screened a pornographic video, the RIA Novosti news agency reported on Thursday.

Hacker Igor Blinnikov stopped traffic in January last year by breaking into a computer system and screening a graphic sex video for around 10 minutes on a video billboard beside a busy highway in central Moscow in the late evening.

Blinnikov, who comes from the southern Russian city of Novorossiisk, was found guilty late Wednesday of illegally gaining access to information on a computer and distributing pornographic materials.

He called the video prank on Moscow's Garden Ring highway a “joke that went wrong” and said that he would appeal against the sentence in a video of the courtroom posted on RIA Novosti's website on Thursday.

He had earlier been convicted of attempting to deal in marijuana and was handed a total sentence of six years by Moscow's Zamoskvoretsky court, a year of which he has already served in detention. - Sapa-AFP