You might want to take a little look at Yahoo’s Web Beacon statement as it sure looks like they are trying to do a FaceBook:
Yahoo! also uses web beacons on and off of Yahoo! for a number of purposes including research and reporting for some of our clients. Please use the second link below to learn more about how we conduct this research and how you can opt-out.
They go on to talk about how they are part of this Network Advertising Initiative however I for one am sick and tired of services and companies making me "opt out" when they should be asking me to "opt in".
Most content on the Internet– from the latest political news to up-to-the-minute sports scores and stock quotes– is free to consumers. Why? Because of effective Internet advertising.
What makes Internet advertising effective is the use of technologies that allow advertising networks to make inferences about consumer tastes and provide relevant content. Because of the seemingly complex nature of these technologies, many users have become concerned about their online privacy. NAI or the We Spy On You Network.
So if your not wanting Yahoo to now spy on you then go here and step through the process which says will stop their spying. Web Beacons