The approximate location of a fixed computer that is connected to the internet can be established by anyone using calculations derived from the machine's IP address, US researchers claim.
Internet service providers (ISPs) issue unique numbers, or IP addresses, to subscribers either on a permanent basis or each time they connect to the internet.
Researchers from the University of Electronic Science and Technology of China (UESTC) have claimed that it is possible to track the location of an internet-connected computer to within an average of 690 metres of its actual location. The researchers said that this is done by working out its relation to known landmarks whose IP addresses and physical addresses are known.
"The high accuracy of our system in a wide range of networking environments demonstrates its potential to dramatically improve the performance of existing location-dependent internet applications and to open doors to novel ones," said the researchers' Towards Street-Level Client-Independent IP Geolocation report (14-page / 331KB PDF).
The researchers recorded the time it took to 'ping' between computer servers. This meant they positioned a computer that was connected to the internet and accessed its server from a number of locations and waited for that information to be sent back. The team then translated the time taken into distance using the speed of light and taking online delays into account.
The information was collated from the test locations and mapped to give an overall view of where the machine approximately was. The information was used to find nearby schools, businesses and public buildings. The researchers narrowed down the computer's location based on calculations from the time it took them to access the computer's server from the servers based at the landmarks.
"Many entities host their web services locally. Moreover, such websites often provide the geographic location of the entity (e.g business and university) in the form of a postal address," the UESTC researchers said in their report.
"We demonstrate that the information provided in this way ... provides access to a large number of highly accurate landmarks that we can exploit to achieve equally accurate geolocation results," the report said.
The researchers' claims could be further investigated by advertisers to serve internet users with more local adverts,technology news service eWEEK Europe said.
"Combining location with the typical socioeconomic status for the location would allow an advertiser or agency to tie in a local business to find potential customers who live within walking distance of their outlet, without breaking any privacy laws," a story on eWEEK Europe said.
"Communications from the pizza place round the corner or the jeweller down the road is just a few hundred pings away," the website said.
Last week European data protection watchdogs the Article 29 Working Party said that geolocation data should be treated as personal data that must be protected under European law.
The Working Party, which is a committee made of up national data protection regulators from the 27 EU member states, said that companies should have to gain users' consent to access the geolocation data.