Most people do not realise how many organisations are collecting their "digital footprints" as they roam the internet and communicate with their friends, so data mining expert Detica is to commission a national survey on the public's changing perceptions of privacy and its limits.
Announcing the study, the head of Detica's technical consulting practice, Anthony Golledge, told Computer Weekly that technology was changing so fast that most people were not aware of how many "digital footprints" they leave as they surf the internet, travel and use their mobile phones.
This is especially the case with smartphones, which give outsiders much greater insight into their owners' lives because of all the things they do with them, said Golledge.
A PoliticsHone survey this month found that 63% of Britons feel the government already collects too much information about them, and only one in four favours data collection and retention by the authorities.
Golledge said many organisations are collecting users' data. Some are using it for legitimate purposes, such as law enforcement and national security or to target advertising, but others are less scrupulous.
Golledge said data mining applications are pushing technology limits. With the number of online transactions growing daily, so much data is generated each day that brute force attempts to identify individuals from the bitstream are unlikely to succeed, he said.
"We need to return to an older strategy, which is to generate a reasonable working hypothesis and test the data against that to find fits," he said.
Golledge said trying to identify individuals using "brute force" was like looking for a needle in a haystack when even the needles looked like hay. "We are at the point when data mining and behaviour targeting are good for identifying classes or short lists of people, but the searcher must use other methods to corroborate the findings and narrow the field further to get to the individual," he said.
Golledge said few people are aware of the data trail left by their use of mobile phones, particularly with respect to location data. "Very few people know that an entire journey can be traced from the log of mobile base stations that pick up the signal from their phone," he said.
Such information is not worth much on its own, but over time it can enable an organisation to build up a detailed picture of the phone owner's movement patterns. Allied to that are calls that they make and receive. This makes it easy to uncover a subject's social network, said Golledge.
"This information is probably even more interesting to investigators and marketers than your name and address," he said.
Golledge said the survey would "take the temperature" of public attitudes to privacy issues over time. Detica expects the results to inform government and large businesses' decision about appropriate steps to take with respect to privacy.