I am just learning about the world of trackers using 3rd party cookies. New security issues are arising that potentially impact the manner we manage patient and student information. More important, these security concerns probably should alter the way we personally interact with Internet-accessible resources. Below I am aggregating links in order to enable you to quickly get up to speed.
The Wall Street Journal is running a series of articles about tracking and personal privacy:
Here is an example from VirtualForge of CrossSite Scripting Vulnerabilities
For Firefox - there is a great plugin: Ghostery that displays what is happening on each web page with respect to cookies and tracking: Ghostery: Firefox plugin
When installed, the plugin displays in the upper right corner a purple rectangle wiht the names of the cookie cooks that planted cookies on your computer. Below is an example from the NY Times that indicates 4 cookies form Comscore Beacon, Doubleclick, Google Adsense and Quantcast.:
C. Frank Starmer