When a criminal uses a computer to commit crimes, law enforcement may be able, through lawful legal process, to identify the computer or subscriber account based on its IP address.
The final few hundred metres to the house will be crossed with a wireless connection, using transmitters mounted on Tepco's electricity poles and tiny receivers plugged into a subscriber's personal computer.
The early-adopter set has been playing with home networking for a few years, but now the technology is spreading to mainstream consumers, who want to split the fast Internet connection of a cable modem or digital subscriber line (DSL) among several PCs, and also share computer files and peripherals such as printers and scanners.