there has been criticism of the extradition act 2003 in the uk in respect of the cases of gary mckinnon and the natwest three. in particular, the act has been criticised for reducing the level of evidence required for extradition from the uk to the u.s. from "prima facie" evidence to "reasonable suspicion", and for allowing extradition to proceed on the basis of offences in u.s. rather than uk law. in addition, the standard of proof required for extradition from the u.s. to the uk is different, in accordance with the fourth amendment – the standard of "probable cause".