Embedded images may be used as a web bug to track users or to relay information to a third party.
Others, like Smartshopper.com, say they track users anonymously, meaning they do not collect personal information.
Over the summer, word of the planned dog run spread to track users, who mobilized in opposition.
In certain countries, it is illegal to track users without their knowledge and consent.
Users can track other users, thus allowing them to see updates for their favorite blogs.
But, they add, the profiling software does not track individual users by name.
The ability to track individual users adds ostensibly little value to the advertiser itself.
In recent weeks, a debate has emerged over new technologies that have been deployed to allow companies to track individual users on the Internet.
Because of this redirection, Microsoft is also able to track users and provide Tag analytics to publishers.
As a bonus, the site does not track users or require them to disclose personal information for access.