Traders are also doing 7% of their volume in "dark pools, " the electronic equivalent of a back alley where buyers and sellers transact anonymously, according to Tabb Group, a Westborough, Mass. market researcher.
And although they cannot compete with aeroplanes for speed, or with water-borne shipping for volume, they could cover in a few days a distance equivalent to a six-week journey by ship.
Desautels says his Apple bug bounty is still around 15% less than he would pay for the equivalent PC-focused flaw, given that high-volume cybercrime is still much more common than targeted espionage.
The United Downs tip is 15m (49ft) deep and has a volume of 250, 000 cubic metres (8.8m cubic ft) - the equivalent of 125 Olympic-sized swimming pools - but the council predicts it will be full by 2010.