A judge has warned about the dangers posed to trials by users of social networking sites after the Crown Prosecution Service had to halt a case.

Anthony Roberts, 22, had been arrested on a charge of unlawful wounding, which he had denied, and a jury was expected to hear the trial.

Canterbury Crown Court heard the evidence of the alleged attack was based on identification evidence from witnesses.

But before the trial started it was revealed the prosecution case was compromised after discussions regarding Roberts had taken place over Facebook - prior to a formal identification taking place.

As a result, the prosecution decided to scrap the case and offer no evidence against Roberts, of Canute Road, Deal, and a formal not guilty verdict was recorded.

Judge James O'Mahony said: "I raise concern about the use of social networking sites, like Twitter and Facebook and other forms of media.

"While admirable although they may be in many ways, they do pose problems in the context of the criminal justice system and this case shows how careful one has to be with juries in trials."

In a separate hearing, Roberts was later jailed for four months for an assault on a pub landlord in 2009.

Michael Newell, who ran the Alma pub in Deal, was punched and kicked while ejecting another man who had been banned for urinating against a wall.

Roberts, who admitted the assault, was told by the judge: "This is a very serious offence. Pub landlords have every right to look to the courts for protection.

"People are sick and tired of seeing drunken violence occurring so regularly."