At the 3rd DRM conference this January in Berlin, Ross Anderson gave a dinner speech in which he envisaged a world suffused by region-coding technology (imagine region-coding in RFID-equipped jeans, e.g.). While we are not at this stage yet (at hopefully will never be), here is just another example of the increasing use of this technology:
"HP has quietly begun implementing 'region coding' for its highly lucrative print cartridges for some of its newest printers sold in Europe. Try putting a printer cartridge bought in the U.S. into a new HP printer configured to use cartridges purchased in Europe and it won't work. Software in the printer determines the origin of the ink cartridge and whether it will accept it. The company introduced region-coding on several printers in the summer so it won't have to keep altering prices to keep pace with currency movements, says Kim Holm, vice president for HP's supplies business in Europe, the Middle East and Africa. HP eventually plans to introduce the concept across its entire line of inkjet printers, he adds." (This is an excerpt from a very interesting Wall Street Journal story).
Of course, this is not a big step from Lexmark's attempt to thwart competition in the cartridge aftermarket (which, from their perspective, is absolutely understandable and the rational thing to do).