The distinction with the NatWest Three though is that the Enron situation meant that there were grounds for the US to have a stake in the prosecution. I can't see in this case how the US have a stake.
I realise that having such a stake is not required by the Treaty, but perhaps it should be?
I'd agree that the US's claim to a stake in the NatWest Three case is probably more legitimate. Of course, TVShack had a lot of commercial activity with US advertisers, but doesn't seem like it would be difficult to establish this in a UK court.
The forum clause, which was passed by both Houses, would require such a stake, but it hasn't been implemented by either the last government or the current one, apparently because it breaks the treaty we signed with the US which led to the act in the first place. A shame, because it looks eminently sensible to me: http://www.legislation.gov.uk/ukpga/2003/41/section/83A
I realise that having such a stake is not required by the Treaty, but perhaps it should be?