Website tracking tags raise privacy fears

More than half of the tracking devices on any major website are not deployed by the site’s owner, a new survey has shown, in results that raise privacy, security and regulatory headaches for online publishers.

Tracking devices such as cookies are increasingly vital for online businesses and are used to determine everything from how long visitors spend on a website, to what adverts they see and even – in some cases – what they pay for a product. They work by installing data on to a visitor’s browser, which is then used to track the user as they move around the web. The majority of tracking devices – 55 percent – used by major websites were put there by third parties, rather than the site’s publisher, meaning that a user’s data can be spread between up to 10 different companies, according to a survey by Evidon, which monitors tracking devices online, based on a panel of 7.5 million internet users, who let the company monitor their browsing habits.