The Law West of Ealing Broadway notes that
The first difference from the British system that they are likely to encounter on arrival in the USA will be the American habit of chaining prisoners hand and foot. This is largely a symbolic humiliation in their case, as it is in many cases, because having reported to Gatwick and got on the plane they are hardly likely to attack their guards and escape.See also:
Friends Extradited - II
Friends Extradited - III
The Friends Extradited website is here.