Recommended Practices for Browser Security and Privacy
Historically, advertisements were limited to operating in one direction: from your newspaper, radio, or television screen to you. Enter the full duplex, bidirectional intertubes, and now advertisers have a slew of lucrative new methods to target the awful nuisance of advertisements to you. The history of sites you visit and your search history (behavioral targeting), the content of the page you’re browsing at the time (contextual advertising), and potentially all sorts of demographic and personally characterizing information may be in scope depending on the application (think e.g. Facebook). …