It is reported that senior Mexican officials including the attorney-general have had identifying chips implanted into their persons. These are intended to control access to sensitive information and provide a means of locating them in the event of kidnapping. Presumably the "chips" are RFID devices, which would emit a radio signal containing a unique identifier when queried by a transmitter.
Of course, they would also provide a means of tracking their location whereever they go. Supposedly, it is widely believed in Mexico that this technology is in common use - a kidnapping gang has emerged that strips its victims and demands under threat of mutilation that they reveal where the device is. The implication is clearly that they would then hack it out of their flesh.
This is, I think, a grim example of a future trend - the increasing use of advanced security technology as a form of class distinction, and its exploitation by the criminals against whom it is directed. After all, the equipment used to query an RFID chip is fairly cheap general purpose technology. If the police, or private interests, can track your location to assure your safety, the kidnappers could use the same technology to find you. They might discover the identity signal, and either monitor the frequency for it or actively broadcast the "ping" to trigger it - giving them the ability to locate and identify you. Sao Paulo has become in recent years a helicopter Mecca as the demand for transport by helicopter ballooned. Fear of kidnapping drove even the middle classes to take to using air taxi services, which was good news for Portuguese-speaking helicopter pilots but probably no-one else. This is the information equivalent, as is the Barcelona nightclub whose members can use an RFID chip to beat the queue past the velvet rope and order drinks on account. That is comic, but the Mexican story is probably more significant.
The danger is that strategems like this, desperate responses to a public sphere and social fabric utterly lacking, will spread. If you can use your RFID tracking gear in Mexico City, why not in London? It is in the nature of complex and interdependent systems that changes in the ephemeral surface can bring about major changes to the structure. When computers were installed as furniture in office buildings, the building services had to change, which could mean quite radical changes in the architecture. The Mexican officials with their microchips have effectively drawn the frontier between Raymond Aron's "world of order" and "world of chaos" on their bodies - kidnapping as a common crime seems to be a phenomenon of those cities on that frontier, like Mexico City, Sao Paulo or indeed Baghdad.