A new study has found that many of the internet's top websites are tracking users without their permission or knowledge.
The researchers discovered that the websites used Flash-based fingerprinting. Some Flash objects included questionable techniques such as revealing a user's original IP address when visiting a website through a third party.
Device fingerprinting, also known as browser fingerprinting, is the practice of collecting properties of PCs and mobile devices to identify and track users. This includes the screen size, the versions of installed software and plug-ins, and the list of installed fonts.
It was also found that users are tracked by these device fingerprinting technologies even if they explicitly request not to be tracked by enabling the Do Not Track (DNT) HTTP header.
Device fingerprinting can be used for various security-related tasks, including fraud detection and protection against account hijacking. But it is also being used for analytics and marketing purposes via fingerprinting scripts hidden in advertising banners.