Hacking into new technology for nefarious reasons isn't exactly new. Only the technology is new. People scheming to profit from someone else's system is as old as time. Such a scheme befell France's government communication system in 1834, which amounted to an old-fashioned game of telephone, but was a great innovation for the time -long before actual telephones.
The world’s first national data network was constructed in France during the 1790s. It was a mechanical telegraph system, consisting of chains of towers, each of which had a system of movable wooden arms on top. Different configurations of these arms corresponded to letters, numbers and other characters. Operators in each tower would adjust the arms to match the configuration of an adjacent tower, observed through a telescope, causing sequences of characters to ripple along the line. Messages could now be sent much faster than letters, whizzing from one end of France to the other in minutes. The network was reserved for government use but in 1834 two bankers, François and Joseph Blanc, devised a way to subvert it to their own ends.
The plan was genius: they conspired to add in a code that they could intercept ahead of their competitors in order to manipulate the market. The Blancs were groundbreakers, in that communications security was a completely new concept and there was no law yet against what they did. Read how they did it at 1843 Magazine. -via Boing Boing