Sandy said almost exactly what I've been thinking: If he has broken a British law, he should be tried in Britain. If he has not broken a British law he is innocent. I find it extroardinary that foreign criminals can get sanctuary in Britain if their own countries have the death penalty or use torture to gain evidence, yet we are prepared to hand this guy over to the United States, where he has never been.
If he really has made a nuisance of himself in some way, perhaps the U.S. should be grateful that this problem with their security was found by someone benign and not by terrorists.
I believe the relevance of Asperger's syndrome is that he may not be good at foreseeing the consequences of his actions.