Once again a performance by the Jerusalem Quartet has been disrupted by bigots. Things hardly started well when the director of the Brighton Festival, Andrew Comben, in an astonishingly crass misjudgment, prefaced the concert with a warning that there was likely to be disruption. The benighted musicians must wonder whether it is worth their while performing in a country that permits these thugs to act with impunity. It is time for the Crown Prosecution Service to make it clear that, while demonstrations outside are perfectly legitimate, those which take place inside, disrupting a performance, will be met with the full force of the law.