The scope of this rule has been considered in cases when much of the prosecution case involves evidence by a witness who is absent from court. In "Luca v Italy" (2003), in the European Court of Human Rights, it was held that a conviction solely or decisively based upon evidence of witnesses which the accused has had no opportunity to examine breached Article 6 of the Convention (right to a fair trial). However in "R v Arnold" (2004), in the Court of Appeal, it was said this rule would permit of some exceptions, otherwise it would provide a licence to intimidate witnesses - though neither should it be treated as a licence for prosecutors to prevent testing of their case. Each application had to be weighed carefully.