Z:gnu-www-ja-keep-control-of-your-computing--02a907-Developments in the Web threat/en

Developments in the Web threaten to negate this achievement. The first problem was the use of invisible references to sites whose mission was surveillance (perhaps for advertising). Users who visited sites A, B, X and Z did not realize that those pages contained invisible references to iamwatchingyou.com, so each visit informed that site too, and it recorded permanently that this user had visited certain pages.